  April 16, 1993
                    UNITED STATES COURT OF APPEALS
                        FOR THE FIRST CIRCUIT

No. 91-1890

                      UNITED STATES OF AMERICA,

                              Appellee,

                                  v.

                           MICHAEL BARNETT,

                        Defendant, Appellant.

                                             

No. 91-1891

                      UNITED STATES OF AMERICA,

                              Appellee,

                                  v.

                            BARRY JORDAN,

                        Defendant, Appellant,
                                             

No. 92-1778

                      UNITED STATES OF AMERICA,

                              Appellee,

                                  v.

                            BARRY JORDAN,

                        Defendant, Appellant.

                                             

                             ERRATA SHEET

    The opinion  of this Court  issued March 29,  1993, is  amended as
follows:

    Page 22, line  two of text after block  quote, should read:  . . .
476 U.S. 1115 (1986) . . . . 

April 7, 1993
                    UNITED STATES COURT OF APPEALS
                        FOR THE FIRST CIRCUIT
                                             

No. 91-1890

                      UNITED STATES OF AMERICA,

                              Appellee,

                                  v.

                           MICHAEL BARNETT,

                        Defendant, Appellant.

                                             

No. 91-1891

                      UNITED STATES OF AMERICA,

                              Appellee,

                                  v.

                            BARRY JORDAN,

                        Defendant, Appellant,
                                             

No. 92-1778

                      UNITED STATES OF AMERICA,

                              Appellee,

                                  v.

                            BARRY JORDAN,

                        Defendant, Appellant.

                                             

                                  3

                             ERRATA SHEET

    The  opinion of  this Court issued  March 29, 1993,  is amended as
follows:

    Page 28, last line of  text, should read:  . . . since there  were
none.

March 29, 1993
                    UNITED STATES COURT OF APPEALS
                        FOR THE FIRST CIRCUIT
                                             

No. 91-1890

                      UNITED STATES OF AMERICA,

                              Appellee,

                                  v.

                           MICHAEL BARNETT,

                        Defendant, Appellant.

                                             

No. 91-1891

                      UNITED STATES OF AMERICA,

                              Appellee,

                                  v.

                            BARRY JORDAN,

                        Defendant, Appellant,
                                             

No. 92-1778

                      UNITED STATES OF AMERICA,

                              Appellee,

                                  v.

                            BARRY JORDAN,

                        Defendant, Appellant.

                                             

                                  5

            APPEALS FROM THE UNITED STATES DISTRICT COURT

                  FOR THE DISTRICT OF MASSACHUSETTS

             [Hon. Joseph L. Tauro, U.S. District Judge]
                                                       

                                             

                                Before

                         Breyer, Chief Judge,
                                            

                   Cyr and Boudin, Circuit Judges. 
                                                 

                                             

    Gayle C.  Wintjen with whom McGuinness  &amp; Parlagreco  was on brief
                                                        
for appellant Michael Barnett.
    George F. Gormley for appellant Barry Jordan.
                     
    Joseph M.  Walker III, Assistant United States Attorney, with whom
                         
A. John Pappalardo, United States Attorney, was on brief for appellee.
                  

                                             

                            March 29, 1993
                                             

    CYR, Circuit Judge.  Appellants  Michael Barnett and  Barry Jordan
    CYR, Circuit Judge.
                      

were charged, in a three-count indictment, with conspiracy to manufac-

ture and  possess with intent to distribute  methamphetamine in viola-

tion of 21 U.S.C.   846, possession with intent to distribute  metham-

phetamine in violation of 21 U.S.C.    841(a) (1), and possession of a

listed  chemical in violation  of 21 U.S.C.    841(d)(1).  Barnett was

convicted on all three  counts at trial; Jordan pleaded  guilty to all

three  counts shortly  after  the commencement  of  trial.   Each  was

sentenced  to a thirty-year prison term  and a ten-year term of super-

vised  release.  On appeal,  Barnett raises several  challenges to his

conviction, and  joins Jordan in contesting  the drug-quantity finding

made by the district court at sentencing.  We affirm.  

                                  I

                              BACKGROUND
                                        

    In March  1990, the United  States Drug Enforcement Agency ("DEA")

began investigating a suspected conspiracy to manufacture and distrib-

ute methamphetamine.  Surveillance was initiated at three sites in the

Scituate,  Massachusetts area:   the residences of  each appellant and

the residence of their codefendant, Timothy Fitzgerald.1  

    Approximately a  year before  the investigation  began, a  trailer

storage  company had  delivered a  forty-foot trailer  to Fitzgerald's

                    

     1Fitzgerald was acquitted at trial.

                                  3

residence  in  Scituate.   The employee  who  made the  delivery later

testified that the  recipient of the  trailer, known to him  as "Tim,"

instructed that the trailer be placed as far back as possible into the

woods  located on  the  property.    Barnett subsequently  rented  the

trailer from Fitzgerald.

    In  early May, 1990,  undercover DEA  Agent John  Kelly offered to

sell  Jordan hydriodic  acid ostensibly  stolen by  Kelly.2   At their

meeting, Jordan  explained that his "chemist"  had enough pseudoephed-

rine to produce forty  pounds (eighteen kilograms) of methamphetamine,

but  needed  twenty  pints of  hydriodic  acid  for the  manufacturing

process.   During their  tape-recorded conversation, Jordan  agreed to

buy twenty  pints of hydriodic  acid, and  to provide Kelly  with four

ounces of methamphetamine  in return.   Jordan assured  Kelly that  he

would  receive four  "uncut" ounces,  and suggested  that Kelly  could

double the volume by  diluting the pure methamphetamine with  an equal

amount of "cut," then  sell the resulting  eight ounces for $2,000  an

ounce.

    Jordan  described  the methamphetamine  manufacturing  process  to

Kelly, explaining  that it  took seven  to  eight days,  and that  his

chemist  produced ten  pounds of  methamphetamine in  each batch.   To

allay  Kelly's concern  about the  danger of  a laboratory  explosion,

                    

     2Hydriodic acid,  a listed chemical, is  essential to methamphet-
amine production  using the "ephedrine reduction  process," which also
requires either ephedrine or  pseudoephedrine; red phosphorus may also
be used as  a purifying agent.   To convert  the methamphetamine  into
powder for  distribution,  it is  dissolved  into freon  liquid,  then
bubbled in hydrogen chloride gas.

                                  4

Jordan explained  that his chemist had  been manufacturing methamphet-

amine for ten years, and volunteered that he had assisted  the chemist

in preparing eight to ten batches one summer.3

    As promised, on May 16, 1990,  Kelly delivered two boxes  contain-

ing  twenty half-liter  bottles (approximately  twenty pints)  of hyd-

riodic  acid to  Jordan.   A different  DEA agent  followed  Jordan to

Barnett's residence,  where he  observed Jordan and  Barnett unloading

two boxes from the trunk of Jordan's car.

    The  DEA  conducted a  series  of  aerial  surveillance  fly-overs

during  May 1990.  A fly-over of  the Fitzgerald residence on or about

May 27 revealed an electrical  power cord running from the  main house

to the trailer.   (The  ephedrine reduction process  requires a  power

source to heat the chemicals.)

    Two subsequent  fly-overs of  the Fitzgerald  residence were  con-

ducted  using  an infrared  heat-detecting  device  which operates  in

either of two  polarity modes:  "white-hot" or  "black-hot."  When the

device is in the white-hot mode, objects emitting heat appear white on

an  attached  screen; in  the  black-hot  mode, heat-emitting  objects

appear black.  The  device detected no heat emission  from the trailer

during a  fly-over on May 28.   On May 30,  Massachusetts State Police

                    

     3After pleading guilty during  trial, Jordan submitted an affida-
vit  in which he insisted  that these statements  were mere "puffing,"
intended to  convince Kelly that he  was willing and able  to complete
their transaction.   The affidavit  attests that  Jordan knew  nothing
about  the manufacture of methamphetamine,  and that his  only role in
the  enterprise was to obtain  hydriodic acid in  exchange for a small
amount of money to support his heroin habit.

                                  5

Trooper Richard Welby, who  had relatively little experience  with the

infrared equipment,  conducted another  fly-over.  Welby,  erroneously

believing  the device  was in  the white-hot  mode, observed  that the

trailer  appeared white  on  the screen,  and  concluded that  it  was

emitting heat.  Subsequent analysis revealed, however, that the device

actually was in the black-hot mode during the May 30 fly-over, and the

infrared images, properly interpreted,  indicated that the trailer was

emitting no detectible heat.

    On the afternoon  of May 30, a DEA  agent followed Barnett to  the

Fitzgerald property.  When Barnett disappeared  down the driveway, the

agent  left his  vehicle and  surreptitiously followed  on foot.   The

agent spotted the  trailer and saw Barnett inside.   The agent noticed

several  blue buckets, a white radiator, and  two boxes in the rear of

the trailer.   As the agent watched, Barnett scraped the bottom of one

of the blue buckets for approximately five minutes, then poured liquid

into the bucket.  Barnett left the trailer and entered the main house,

returning  with several paper towels with which he filtered the yellow

slushy contents of the bucket, then poured the filtered substance into

a  gray painter's tray.  Barnett made  another trip to the main house,

this time  returning with clear plastic  sandwich bags.  He  picked up

the gray painter's tray, rocked it back and forth  several times, then

poured the yellow slushy substance into one of the bags, double-bagged

it, and returned once again to the main house.

    The DEA agent returned  to his vehicle, and  waited for Barnett to

drive  away.   After  about  twenty-five  minutes,  Barnett  left  the

                                  6

Fitzgerald  property and drove to  a shopping center,  unaware that he

was  being followed  by the  agent.   When the  agent pulled  into the

shopping  center parking lot, he  noticed a second  individual in Bar-

nett's  vehicle.  The agent identified the second individual as appel-

lant Jordan.

    On May 30, DEA Agent Lemon  compiled the information obtained from

the  various surveillance  operations  (including the  erroneous heat-

imaging  data interpretation) in an affidavit, which he attached to an

application  for a  warrant to  search the  trailer on  the Fitzgerald

property,  the  Fitzgerald  and  Jordan residences,  and  a  residence

believed to be occupied by Barnett.

    The  investigation culminated  early  the next  morning  when  the

search warrants were executed.  First, agents searched the  Fitzgerald

trailer,  unveiling a  partially  assembled laboratory  containing  an

array  of chemicals,  including  hydriodic acid,  acetone, freon,  and

hydrogen chloride gas,  and an assortment of equipment associated with

methamphetamine  production,  including  a radiator,  a  fan,  flasks,

tubes, and a heater-timer.   Three ounces of methamphetamine  crystals

and  a bucket  containing approximately  one pound  of methamphetamine

crystals  in two and one-half pounds of an acetone/freon solution were

also discovered.  Subsequent  analysis determined that the methamphet-

amine found in the bucket was between 90 and 100 percent pure.

    DEA  agents arrested  Jordan and  Fitzgerald at  their  respective

residences.   At Jordan's residence, agents seized a small quantity of

a mixture containing heroin  and methamphetamine, as well as  a valium

                                  7

tablet,  several hypodermic needles, and several publications describ-

ing  the  methamphetamine  manufacturing  process.    At  Fitzgerald's

residence, agents found a piece of paper listing the chemical ingredi-

ents needed  to produce methamphetamine using  the ephedrine reduction

process ("the Fitzgerald chemical list").

    Barnett no  longer resided at the  residence for  which the fourth

search warrant had been obtained.  When DEA agents arrested Barnett at

his new residence, he was  advised of his Miranda rights and  that the
                                                 

laboratory  had been  discovered at  the Fitzgerald property.   Agents

searched  Barnett's new  residence,4  and discovered  a warehouse  re-

ceipt.   In response to a question from Agent Lemon about the receipt,

Barnett  revealed that the remaining equipment and chemicals were in a

storage bin at the warehouse.  A warrant was secured and the search of

the storage bin uncovered approximately fifteen pounds of red phospho-

rous,  a  seventy-pound drum  containing  an  unspecified quantity  of

hydriodic acid, a fifty-kilogram container of pseudoephedrine slightly

less than half full, and  various other chemicals, glassware,  cooking

devices, protective gear and gloves.

    At  DEA headquarters,  after  determining that  Barnett  had  been

advised  of his  Miranda rights,  DEA agent  Boeri engaged  Barnett in
                        

conversation  about the  methamphetamine  operation.   In response  to

Boeri's questions,  Barnett admitted that he was  the "chemist," indi-

cated that he  had experienced no difficulty  obtaining chemicals, and

                    

     4Barnett contests the district  court ruling that the warrantless
search was consensual.  See infra at pt. II.B.1.
                                 

                                  8

explained that his methamphetamine  was "ninety nine and  one percent"

pure  as a  consequence  of the  two  "extra" manufacturing  steps  he

performed.

    Five  days into their  joint trial,  Jordan pleaded  guilty to all

counts.    Thereafter,  the  jury  convicted  Barnett,  and  acquitted

Fitzgerald, on all counts.

                                  II

                              DISCUSSION
                                        

A.  Sentencing Issues
                     

    Barnett and Jordan challenge  the sentencing court's determination

that  each was responsible  for twenty-nine kilograms  of pure metham-

phetamine.   Jordan alone contests the court's drug purity ruling.  We

review for  clear error,  see 18  U.S.C.    3742(e); United  States v.
                                                                   

Panet-Collazo, 960 F.2d 256,  262 (1st Cir.), cert. denied,     U.S.  
                                                                      

,  113 S. Ct. 220  (1992); United States v.  Weston, 960 F.2d 212, 220
                                                   

(1st  Cir. 1992), with a view to  whether the factual findings made by

the sentencing court were supported by a preponderance of the reliable

information.  See, e.g., United States v. Rodriguez-Cardona,  924 F.2d
                                                           

1148, 1155 (1st  Cir.), cert. denied,       U.S.     ,  112 S. Ct.  54
                                                     

(1991); United States  v. Zuleta-Alvarez,  922 F.2d 33,  37 (1st  Cir.
                                        

1990), cert. denied,     U.S.    , 111 S. Ct. 2039 (1991).
                   

    1.Drug Quantity
                   

    The  district court adopted the drug-quantity findings  set out in

                                  9

the presentence reports  ("PSRs").5   Each PSR  provided, in  relevant

part:

    In  this offense, the defendant secured a 50 kilogram drum of
    pseudoephedrine which would make 29 kilograms of pure metham-
    phetamine.   There was  every indication  that  they had  the
    materials to produce  this full  amount.  As  such, the  Drug
    Quantity Table  under [s]ubsection (c), offenses involving at
    least 10 kilograms but less than 30 kilograms of pure metham-
    phetamine provides for a base offense level of 40.

Appellants insist that the court  overestimated the capacity of  their

drug manufacturing operation and that their sentences should have been

based exclusively on the quantity of methamphetamine seized.

    The sentencing guidelines direct that  a defendant who is convict-

ed  of  conspiring or  attempting to  commit  any offense  involving a

controlled substance shall be assigned the same base offense level "as

if  the object  of  the conspiracy  or  attempt had  been  completed."

U.S.S.G.    2D1.4.   Further  guidance is  provided in  an application

note:

    Where there is no drug seizure  or the amount seized does not
                                                                 
    reflect the  scale of the offense, the sentencing judge shall
                                     
    approximate  the quantity  of the  controlled substance.   In
    making his  determination, the judge may  consider, for exam-
    ple,  the price  generally obtained  for the  controlled sub-
    stance,  financial or other  records, similar transactions in
    controlled  substances  by the  defendant,  and  the size  or
                                                                 

                    

     5Appellants mistakenly  suggest that  the court made  no specific
finding as  to the quantity  of drugs for  which they were  being held
responsible.  The court checked the  box on the "Statement of Reasons"
form  attached  to the  judgment relating  to each  defendant, thereby
clearly indicating  that "[t]he  court adopt[ed] the  factual findings
and  guideline application in  the presentence report."   We therefore
reject their Rule 32(c)(3)(D) claim.

                                  10

    capability of any laboratory involved.
                                         

U.S.S.G.   2D1.4, comment. (n.2) (1991) (emphasis added).

    Three ounces of methamphetamine crystals, and a bucket  containing

an additional  pound of methamphetamine  crystals in two  and one-half

pounds  of  liquid, were  seized.   Nevertheless,  the  district court

reasonably concluded  that the quantity of  methamphetamine seized did

not accurately reflect the  scale of the offense, see  id., especially
                                                          

in  view of  Jordan's admissions  that his  "chemist" had at  hand the

ingredients with which to produce forty pounds of methamphetamine, and

in view of the  equipment found in  the trailer and storage  facility,

and the  sizable quantities  of precursor  chemicals seized.   Accord-

ingly,  under the sentencing guidelines the district court did not err

in estimating the drug quantity.

    The  court based  its drug-quantity  calculation on the  amount of

methamphetamine  producible with  fifty kilograms  of pseudoephedrine.

Barnett and  Jordan object to  this calculation because  it disregards

the  undisputed  fact  that  the fifty-kilogram  drum  contained  only

twenty-three kilograms of  pseudoephedrine when it was  seized.  More-

over, Jordan insists that the court's approximation of the quantity of

methamphetamine was flawed because other essential precursor chemicals

were not  seized  in the  quantities required  to produce  twenty-nine

kilograms of methamphetamine, in particular hydriodic acid.

    In approximating  the producible quantity of controlled substance,

the  sentencing court may  consider the amount  of precursor chemicals

                                  11

possessed.  See, e.g., United States  v. Beshore, 961 F.2d 1380, 1383-
                                                

84 (8th Cir.), cert. denied,     U.S.     , 113 S. Ct. 241 (1992), and
                                          

cert. denied,      U.S.     , 113 S. Ct. 243  (1992); United States v.
                                                                   

Short, 947 F.2d 1445, 1456-58 (10th Cir. 1991), cert. denied,     U.S.
                                                            

   , 112 S. Ct. 1680  (1992); United States v. Aichele, 941  F.2d 761,
                                                      

766 (9th Cir.  1991); United  States v. Macklin,  927 F.2d 1272,  1281
                                               

(2nd Cir.), cert. denied,     U.S.    , 112 S. Ct.  146 (1991); United
                                                                      

States  v. Kingston,  922 F.2d  1234, 1236-38  (6th Cir.  1990), cert.
                                                                      

denied,      U.S.     ,  111  S. Ct.  2054  (1991);  United States  v.
                                                                  

Smallwood, 920 F.2d 1231,  1236-38 (5th Cir.), cert. denied,      U.S.
                                                           

   , 111 S. Ct. 2870 (1991).  Although the sentencing court must "'err

on the side of caution'" in selecting from among plausible alternative

drug-quantity  estimates, United  States v. Sklar,  920 F.2d  107, 113
                                                 

(1st Cir. 1990)  (quoting United States v. Walton, 908 F.2d 1289, 1301
                                                 

(6th  Cir.), cert.  denied,     U.S.   ,  111 S.  Ct. 273  (1990)), we
                          

cannot  conclude that its approximation  is constrained by the precur-

sor-chemical quantities actually seized, see Beshore, 961 F.2d at 1383
                                                    

(approximation of drug quantity "does not require that every precursor

chemical be present").  Rather, U.S.S.G.    2D1.4 expressly authorizes

consideration of the size or capability of any laboratory.  See United
                                                                      

States v.  Havens, 910 F.2d  703, 705 (10th Cir.  1990), cert. denied,
                                                                     

    U.S.    , 111 S.  Ct. 687 (1991) (explaining that  a drug-quantity

estimate "should  be equal to the  amount of drugs produceable  if the

precursor  chemicals possessed  by  the defendant  were combined  with

proportionate amounts of the  missing ingredients including processing

                                  12

equipment"); see also  United States  v. Bertrand, 926  F.2d 838,  846
                                                 

(9th Cir. 1991) (finding no clear error in drug-quantity approximation

based  on capacity  of  methamphetamine lab,  notwithstanding lack  of

hydriodic acid); Smallwood, 920  F.2d at 1237 (upholding drug-quantity
                          

finding notwithstanding absence  of precursor  chemicals); cf.  United
                                                                      

States  v. Gerante,  891  F.2d 364,  368-70  (1st Cir.  1989)  (basing
                  

approximation of  drug quantity on discovery  at defendant's residence

of $68,000 believed to be proceeds from recent drug sale).   As we see

it,  the quantity  of essential  precursor chemicals seized,  like the

capacity  of the laboratory and  the evidence relating  to the overall

scheme, see Smallwood, 920 F.2d  at 1237-38, is but one  among several
                     

circumstantial factors appropriately  considered in approximating drug

quantities for sentencing purposes.

    We must  determine  whether  the government  presented  sufficient

reliable  information to permit the court  reasonably to conclude that

appellants were responsible for a quantity of drugs at least equal  to

the  quantity  threshold for  the assigned  base  offense level.   See
                                                                      

Sklar, 920 F.2d  at 113.  The base offense  level assigned each appel-
     

lant  was 40, the level  applicable to offenses  involving between ten

and  thirty kilograms of unadulterated methamphetamine.  A DEA chemist

testified at trial that fifty kilograms of pseudoephedrine would yield

twenty-nine kilograms  of methamphetamine.6  Utilizing  the same ratio

                    

     6Jordan points  out  that the  court did  not state  that it  was
relying on the DEA chemist's testimony, that the drug quantity approx-
imation in the PSR is  not attributed to the chemist, and  that Jordan
had  no opportunity to cross-examine  the chemist, who testified after

                                  13

   one  unit of pseudoephedrine per  a .58 unit of  methamphetamine   

the  twenty-three kilograms  of pseudoephedrine  seized in  the fifty-

kilogram drum would yield  approximately thirteen kilograms of metham-

phetamine,  a quantity sufficient to warrant the base offense level of

40.  

    The DEA  chemist further  testified that  the ephedrine  reduction

process requires hydriodic acid  in quantities from one to  four times

the amount of pseudoephedrine, depending upon the particular "recipe."

Although the evidence does not establish the exact amount of hydriodic

acid the  defendants possessed, approximately ten  liters were seized,

along  with an unspecified quantity found in a seventy-pound container

at  the warehouse.  In addition, an empty seventy-pound hydriodic acid

container was found at the trailer.

    Furthermore,  Jordan admitted  to  Agent  Kelly that  he  and  the

"chemist" had all the necessary ingredients, with the exception of the

hydriodic acid being  procured from Kelly,  with which to  manufacture

forty pounds (eighteen kilograms) of methamphetamine immediately.  The

court also  had before  it the  Fitzgerald  chemical list,  reflecting

chemical quantities  sufficient to produce at  least twenty-nine kilo-

                    

Jordan had entered his guilty plea. 
    "A sentencing hearing need not meet all the procedural  safeguards
and strict  evidentiary  limitations of  a criminal  trial."   Zuleta-
                                                                      
Alvarez,  922 F.2d at 36.  The  sentencing court may rely on extrinsic
       
evidence which  was not  subjected to  cross-examination,  so long  as
there are "'sufficient indicia of  reliability to support its probable
accuracy.'"   Id. at 36 (quoting U.S.S.G.    6A1.3).  Jordan failed to
                
present any evidence at sentencing to refute the drug-quantity approx-
imation  in the  PSR.   We discern  no clear  error in  the sentencing
court's reliance on the DEA chemist's trial testimony.

                                  14

grams of methamphetamine.  Some quantity  of each chemical on the list

was seized  either from the trailer  or the warehouse and  in the size

container specified on the  list.7  Appellants' PSRs also  contain the

uncontroverted  statements that  Barnett produced  approximately eight

pounds of methamphetamine in December 1989 and that Jordan participat-

ed in  its distribution.   Neither appellant  presented countervailing

drug-quantity or chemical-quantity evidence at sentencing.  

    We discern  no clear  error.   The  district court  had before  it

sufficient reliable  information to support a finding that Barnett and

Jordan  were actually responsible for  not less than  ten kilograms of
                                               

methamphetamine, warranting a base offense level of 40.  

    2.  Drug Purity
                   

    An explanatory note  appended to the  Drug Quantity  Table distin-

                    

     7The Fitzgerald chemical list reads as follows:
    d-pseudoephedrine Hcl.
    50 kilo drum
    Hydriodic Acid
    4 - 70 lb drum

    Red Phosphorus
    15 lb
    R-IIFreon
    7 - 100 lb drums
    Methyl Alchohol [sic]
    (methanol)
    5 - 5 gal drums
    Acetone
    7 - 5 gal drums

Among the seized chemicals were a partially filled fifty-kilogram drum
of pseudoephedrine,  one empty and one  partially filled seventy-pound
hydriodic acid  drum, several one-pound  bottles of red  phosphorus, a
100-pound drum  of freon, several five-gallon  containers of methanol,
and two five-gallon acetone containers.

                                  15

guishes  between  the terms  "methamphetamine  (actual)" and  "metham-

phetamine":

    Unless otherwise  specified, the weight of  a controlled sub-
    stance set forth in the table  refers to the entire weight of
    any mixture  or substance  containing a detectable  amount of
    the controlled substance . . . .  The term[] . . . "[m]etham-
    phetamine (actual)" refer[s] to  the weight of the controlled
    substance, itself, contained in the mixture or substance.

U.S.S.G.    2D1.1(c).  The table prescribes a base offense level of 40

for offenses  involving between ten  and thirty kilograms  of "metham-

phetamine (actual)," whereas the same quantity of adulterated "metham-

phetamine"  carries a base  offense level of  36.  Now,  for the first

time, Jordan argues  that the record does not  establish the purity of

the  methamphetamine for which he  was held responsible,  and that his

base offense level should  have been computed under the  Drug Quantity

Table entry for adulterated "methamphetamine" rather than "methamphet-

amine (actual)."  

    Issues  not squarely  raised in  the  district  court will  not be

entertained on appeal.  See United  States v. Haggert, 980 F.2d 8, 10-
                                                     

11  (1st  Cir. 1992)  (collecting  cases).   Although  defense counsel

consistently  referred  to   base  offense  levels   corresponding  to

adulterated "methamphetamine" rather than  "methamphetamine (actual),"

both at  sentencing and in  opposition to the PSR,  at no time  did he

expressly  raise  drug  purity as  an  issue  in  the district  court.

"Judges  are not expected to be mindreaders.  Consequently, a litigant

has  an obligation to spell out [his] arguments squarely and distinct-

ly, or  else forever hold [his] peace."  United States v. Zannino, 895
                                                                 

                                  16

F.2d  1, 17 (1st Cir.)  (internal citations and  quotation marks omit-

ted), cert. denied, 494 U.S. 1082 (1990).  The drug-purity  claim must
                  

be deemed waived, as it was never raised below.8

B.  Suppression Issues
                      

    1.  The Consensual Search
                             

    Barnett  filed a  pretrial  motion to  suppress  certain  physical

evidence and admissions,  on the  ground that he  did not  voluntarily

consent  to the  warrantless search  of his  residence.   The district

court disagreed.  We review for clear error.  United States v. Wilkin-
                                                                      

son, 926 F.2d 22, 24 (1st Cir.),  cert. denied,    , U.S.    , 111  S.
                                              

Ct. 2813 (1991); United States v. Twomey, 884 F.2d 46, 51-52 (1st Cir.
                                        

1989), cert. denied, 496  U.S. 908 (1990).  A  warrantless residential
                   

search violates the Fourth Amendment unless it comes within one of the

"'few  specifically  established  and well-delineated  exceptions[,]'"

                    

     8The  raise-or-waive rule  will  be relaxed  only in  exceptional
cases involving a gross miscarriage of justice where the belated claim
is  "'so  compelling as  virtually  to  insure appellant's  success.'"
Johnston v.  Holiday Inns,  Inc., 595  F.2d 890,  894 (1st  Cir. 1979)
                                
(quoting  Dobb v. Baker,  505 F.2d  1041, 1044  (1st Cir.  1974)); see
                                                                      
United States  v. Slade, 980 F.2d 27, 31 (1st Cir. 1992); Haggert, 980
                                                                 
F.2d at 10-11; Hernandez-Hernandez v. United States, 904 F.2d 758, 763
                                                   
(1st Cir. 1990).  This narrow  exception is unavailing in the  present
case. 
    The  sentencing court  had before  it evidence  that  Barnett per-
formed extra manufacturing steps to assure maximum purity, that Jordan
promised  to  deliver "uncut"  methamphetamine  to  Agent Kelly,  that
Barnett  boasted  to Agent  Boeri  that his  methamphetamine  had been
analyzed "ninety-nine  and one  hundred percent"  pure,  and that  the
methamphetamine  seized at  the  trailer was  between  ninety and  one
hundred percent pure.   Absent any  evidence that the  methamphetamine
was diluted or  adulterated in  any manner, the  sentencing court  was
presented with insufficient evidence to sustain Jordan's present drug-
purity claim.

                                  17

Schneckloth v. Bustamonte, 412  U.S. 218, 219 (1973) (quoting  Katz v.
                                                                   

United States,  389 U.S.  347, 357 (1967)),  which include  consensual
             

searches, id. at  219, 228.  The voluntariness of  a consent to search
             

turns on an assessment  of the totality of the circumstances.   United
                                                                      

States  v. Mendenhall, 446 U.S. 544, 557 (1980); Schneckloth, 412 U.S.
                                                            

at 227.  Among the individualized factors bearing on the vulnerability

of the consenting party  are age, education, experience, intelligence,

and  knowledge of the right to withhold consent.  More general consid-

erations  include whether the consenting  party was advised  of his or

her constitutional rights  and whether  permission to  search was  ob-

tained by  coercive means or under  inherently coercive circumstances.

Id.  at 226;  Twomey, 884  F.2d at  51.   Although sensitivity  to the
                    

heightened possibility  of coercion is appropriate  when a defendant's

consent  is obtained during custody, see Schneckloth, 412 U.S. at 240,
                                                    

n.29,  "custody alone has never  been enough in  itself to demonstrate

. . . coerced . . . consent to search."  United States  v. Watson, 423
                                                                 

U.S. 411, 424 (1976).

    Barnett argues  that his consent  was coerced, in that  he was met

at the  door of his home  by seven or eight  law enforcement officers,

with  guns drawn.  Immediately  after he was  arrested and handcuffed,

the  officers  holstered their  weapons  and  advised Barnett  of  his

Miranda  rights.   Barnett was  then asked  if he  would consent  to a
       

                                  18

search of  the premises.9  Barnett  claims that he was  never informed

that he  could withhold his consent, he was given no consent form, and

he was led  to believe that the officers already  had a search warrant

because they  began searching the premises  immediately upon entering,

prior to requesting consent.

    Written consent is not essential to  the establishment of a  valid

consensual search.  See, e.g., United States v. Chaidez, 906 F.2d 377,
                                                       

382 (8th Cir. 1990) (search may be justified by voluntary oral consent

even  in the  absence  of valid  written  consent); United  States  v.
                                                                  

Castillo,  866 F.2d 1071, 1082 (9th Cir. 1988) (defendant's refusal to
        

sign a consent  form does  not preclude a  finding of  voluntariness).

Moreover,  it  is not  essential that  the  officers first  inform the

consenting party of the right to withhold consent, though knowledge of

the right  to withhold consent is a factor to be considered in assess-

ing voluntariness, Schneckloth, 412  U.S. at 227; see also  Florida v.
                                                                   

Rodriguez, 469 U.S. 1, 6-7 (1984).
         

    Although Barnett testified  that agents began "searching,  looking

under  things," and  "opening drawers  and cabinets,"  Lemon testified

                    

     9Barnett testified  that, following  his arrest, he  was told  by
Agent Lemon:   "Mike, we  are just going to  look around and  take you
down  to  the Marshfield  Police  Station,  okay?"   Barnett  replied,
"Okay."   Barnett contends that he was merely acknowledging his arrest
and inevitable booking, not  consenting to a search of  his residence.
Based  on  Agent  Lemon's testimony,  however,  the  court  found that
Barnett was  asked:  "Mind if I look around the house?" and responded,
"Go ahead.  You'd probably get a search warrant anyway."  The district
court was presented with a pure credibility determination.  We find no
clear  error in its determination  that Lemon's version  of the events
was more credible.

                                  19

that a protective  sweep was conducted  immediately upon entering  the
                        

premises to ensure that no one else was present.10 Thereafter,     ac-

cording  to Lemon,  the  agents "just  [stood]  around" until  Barnett

consented  to a further search.   We find no clear  error in the trial

court's credibility-based ruling that "a sweep search was conducted."

    Barnett's contention  that the  search conducted immediately  upon

entry led him to believe that the agents already had  a search warrant

cannot  succeed in any event.  The district court expressly found that

Barnett responded as follows to Lemon's request for consent to search:

"Go  ahead.  You'd probably  get a search  warrant anyway[]" (emphasis
                                                         

added), plainly  implying Barnett's understanding that  the agents had

no search warrant and needed his consent.

    Notwithstanding the  inherently unnerving effect  of having numer-

ous  officers arrive  at one's  door with  guns drawn, Barnett  was no

"newcomer"  to  law-enforcement  encounters.   See  United  States  v.
                                                                  

Kimball, 741 F.2d 471, 474 (1st Cir. 1984).  Barnett had been convict-
       

ed of  at least eighteen prior offenses and arrested on at least eight

previous  occasions.  Thus,  we may fairly  presume that  he was "less

likely  than most  to be  intimidated by the  agents' show  of force."

United States v.  Cepulonis, 530 F.2d 238, 244 (1st  Cir. 1976), cert.
                                                                      

                    

     10A  sweep search  is  "narrowly  confined  to a  cursory  visual
inspection  of those places in which a  person might be hiding," Mary-
                                                                      
land v. Buie, 494 U.S. 325, 327 (1990).  The officers are permitted to
            
take  reasonable  steps  to ensure  their  safety,  and may,  "without
probable  cause or  reasonable  suspicion, look  in closets  and other
spaces  immediately adjoining the place of arrest from which an attack
could be immediately launched."  Id.
                                    

                                  20

denied, 426  U.S. 908 (1976), and  cert. denied, 426 U.S.  922 (1976).
                                               

In addition,  before he was asked  to consent to the  search, all guns

had  been holstered  and Barnett  was advised  of his  Miranda rights,
                                                              

"'put[ting] him on notice  that he [could] refuse to  cooperate,'" id.
                                                                      

(quoting Gorman v. United States, 380 F.2d 158, 164 (1st Cir.  1967)).
                                

Finally, there was no  evidence of overt or covert threats or pressure

to exact Barnett's consent.

    In these  circumstances, we  conclude that Barnett's will  was not

overborne,  nor his  "capacity for  self-determination  critically im-

paired."  Schneckloth,  412 U.S. at  225.  Ultimately,  as we are  not
                     

"'left with the definite and  firm conviction that a mistake  has been

committed,'"  Anderson v.  Bessemer  City, 470  U.S.  564, 573  (1985)
                                         

(quoting United States v. United States Gypsum Co., 333 U.S.  364, 395
                                                  

(1948)), we find  no clear  error in the  trial court's  determination

that Barnett's consent was voluntary. 

    2.  The Lemon Affidavit
                           

    Next, Barnett claims that the district  court erred in refusing to

suppress  evidence obtained as a result of alleged false statements in

the  affidavit supporting  the  search warrant  application.   Barnett

contends that  the  erroneous  heat-imaging test  data  in  the  Lemon

affidavit was materially false or included with reckless disregard for

its truth.  Without it, says Barnett, the Lemon affidavit was insuffi-

cient to establish probable cause to search the trailer.

    The district  court conducted an  evidentiary hearing pursuant  to

                                  21

Franks v. Delaware, 438 U.S. 154 (1978).  Franks findings are reviewed
                                                

for clear error.  United States  v. Cole, 807 F.2d 262, 268 (1st  Cir.
                                        

1986), cert. denied,  481 U.S. 1069 (1987).  The  questions for us are
                   

(1)  whether Barnett established by a preponderance of the evidence at

the Franks hearing that the affidavit was perjurious, or prepared with
          

reckless  disregard for  its  truth, and  (2)  whether the  affidavit,
                                        

without  the false  material, was  insufficient to  establish probable

cause  for the search.  If so, the  warrant was void and the fruits of

the search must be suppressed.  Franks, 438 U.S. at 155-56.  
                                      

    Barnett claims that  the heat-imaging data Trooper Welby  provided

to Lemon,  see supra at pp. 5-6, was either deliberately or recklessly
                    

false,  because Welby failed to  inform Lemon that  he lacked training

and  experience  in operating  the device  and  failed to  examine the

device prior to  the May 30 flyover  to determine which  polarity mode

was operative.

    The district  court finding that  Welby did  not act in  bad faith

was not clearly erroneous.  There is no evidence that Welby intention-

ally misinterpreted the data from the infrared equipment.  Rather, the

evidence  strongly  suggests,  just as  the  court  found, that  Welby

sincerely believed, albeit  mistakenly, that the equipment was  in the

"white-hot" polarity mode during the fly-over.

    Neither  is there evidence  that Lemon  knew that the heat-imaging

data was incorrect.  Nevertheless, Barnett argues that Lemon's failure

to make note, in the affidavit, that Welby had little  experience with

the heat-imaging equipment was  a material omission made intentionally

                                  22

or with reckless disregard for the truth.  Although the district court

made no direct finding on this issue, we need not pursue the matter as

the affidavit would have been sufficient without the challenged data.

    "[I]f an  affiant knowingly includes  a false statement  in a
    warrant affidavit, the warrant  will stand if, 'when material
    that is the subject of the alleged falsity or reckless disre-
    gard  is set to one side, there remains sufficient content in
    the  warrant  affidavit  to  support a  finding  of  probable
    cause.'"

United States v. Veillette, 778 F.2d  899, 904 (1st Cir. 1985),  cert.
                                                                      

denied, 476 U.S. 1115 (1986) (quoting Franks, 438 U.S. at 171-72).
                                            

    The Fourth Amendment warrant requirement is met  if the magistrate

had a  "'substantial basis for . . . conclud[ing]' that a search would

uncover evidence of wrongdoing."  Illinois v. Gates, 462 U.S. 213, 236
                                                   

(1983) (quoting Jones  v. United  States, 362 U.S.  257, 271  (1960)).
                                        

Without regard to the incorrect heat-imaging data, the Lemon affidavit

established probable cause  to search the trailer.11   The suppression

                    

     11We  summarize some of the more salient information in the affi-
davit:
    (1)  In March 1990, a  cooperating individual informed Lemon  that
Barry  Jordan and a man  known as "Barney"  were manufacturing metham-
phetamine in the South Shore area, possibly in Scituate.  According to
the informant, Jordan  and "Barney" manufactured ten pounds of metham-
phetamine in November or December of 1989.
    (2)   Jordan told  DEA  undercover  agent Kelly  that he  and  his
chemist had 160 pounds of chemicals, and needed only hydriodic acid to
manufacture  forty  pounds of  methamphetamine.    Kelly supplied  the
hydriodic acid in  exchange for  Jordan's promise to  give Kelly  four
ounces of methamphetamine.
    (3)  Clandestine  methamphetamine labs typically have air vents or
ducts  to dissipate toxic fumes; photographs of the trailer revealed a
"black  bordered area" which Lemon,  based on his experience, believed

                                  23

ruling was not clearly erroneous.

C.  Severance
             

    Next, Barnett claims that denial of his severance motion  violated

his  Sixth Amendment right to  confrontation, as a  consequence of the

prejudice occasioned by the admission in evidence, at the joint trial,

of codefendant  Fitzgerald's  post-arrest statements,  see  Bruton  v.
                                                                  

United States, 391 U.S. 123 (1968), and that he was further prejudiced
             

by the testimony of Fitzgerald's spouse, Sheryl.  

    At trial, Agent Lemon testified as follows:

    I  advised Mr. Fitzgerald  that we had  done a search  on the
    trailer  in his backyard.   I advised Mr.  Fitzgerald that we
    had found a  speed lab,  a methamphetamine lab.   I told  him
    that  I believed another person  was the chemist,  and I also
    told Mr. Fitzgerald  that I  believed he knew  who the  other
    person was and that  this other person was a  chemist . . . .
    He told me he knew who this other person was, but that he did
    not know  that this  person was  involved with  a clandestine
    laboratory.  He stated that he  knew him or this other person
    socially and that he would go  out on occasion and have a few
    drinks with  this other person. . . . Mr.  Fitzgerald told me
    that he rented the trailer out to this other person and  that
    it was  used for  construction. . . . Mr. Fitzgerald  told me
    that  he . . .  did not  know what  was going  on out  in the

                    

to be  a trapdoor or venting area  for a clandestine laboratory inside
the trailer.
    (4)  The  pattern of  electricity consumption suggested the  pres-
ence of  a clandestine lab.   The electricity bills showed  a dramatic
increase in December  1989, the  time period during  which Jordan  and
"Barney" manufactured ten pounds of methamphetamine.
    (5)   During a DEA  flyover on  May 26,  1990, a  DEA agent  first
observed a  power cord running between the trailer and the main house.
During a May 28 flyover, two Massachusetts State Troopers observed the
same cord.
    (6)   A DEA agent observed Barnett mixing and straining a "yellow,
slushy mixture" at the trailer on May 30.
    (7)   The trailer  was located  in a  remote, wooded  location, an
ideal site for a clandestine laboratory.

                                  24

Barnett  objected and moved to strike  on Bruton grounds.12  The court
                                                
    trailer, and I then asked Mr. Fitzgerald how he could explain

    what Mr.  Fitzgerald told me was that  he was in the trailer,
    the  hydrio[d]ic acid label that  was found in  his coat, and

    he saw the bottles  of hydrio[d]ic acid, and that  he removed
    one of the labels because he wanted to find out what it was.

Lemon's testimony  relating his own extrajudicial  statements to Fitz-

                                  25
     13Although Barnett moved to  strike the "entire conversation," he
did so  on Bruton grounds  only.   No separate objection  was made  to
                 
given.
against Fitzgerald.  No limiting instruction was requested, offered or

Fitzgerald about "the chemist," no Bruton problem was presented and no
                                         
the Lemon testimony related the extrajudicial statements Lemon made to
                                                              
    There  was no confrontation  clause violation.   First, insofar as

     12At sidebar, the following exchange occurred:

                    
hearsay objection was made.13   Even Fitzgerald's extrajudicial state-
                                                 
sustained the Barnett  objection, but allowed  the testimony to  stand

    T     H     E                 C     O     U     R     T     :

    MR. HORAN:I would still contend that all along [for Barnett]:
    the statement was  sanitized so to speak, but the implication

    MR. KENDALL:He  will.    What  the  Government  would  [AUSA]
    is still clear by the Government that the person who is being

confessing  to anything" and was  a mere "fact  witness" is reversible
    anything.  He's a fact witness.
    T     H     E                 C     O     U     R     T     :
    talked about here is Michael Barnett.

    Let's  assume  it  is.    He  [Fitzgerald]  is  not  confessing to

    nett, or, conversely, it is only to Fitzgerald.

Barnett  contends that  the court's comment  that Fitzgerald  "was not
    agree to is the  statement will not be admitted  against Bar-
    How is this based under the Bruton issue?
                                      

error.  This argument is baseless.
ments to Lemon neither  identified nor inculpated Barnett,  but merely

related  factual observations  established by  other  independent evi-

dence.  Second,  assuming the jury did  deduce, as seems  likely, that

Lemon and  Fitzgerald were  referring to Barnett,  Fitzgerald's state-

ments nonetheless did not entail  the sort of "'powerfully incriminat-

ing' effect of one accomplice pointing the finger directly at another,

without subjecting  himself to  cross-examination."  United  States v.
                                                                   

DiGregorio, 605 F.2d 1184, 1190 (1st Cir.), cert. denied, 444 U.S. 937
                                                        

(1979), and cert.  denied, 444 U.S. 944 (1979), and  cert. denied, 444
                                                                 

U.S. 983  (1979) (quoting Bruton, 391  U.S. at 135).   See also United
                                                                      

States  v.  Greenleaf, 692  F.2d 182,  188-89  (1st Cir.  1982), cert.
                                                                     

denied,  460  U.S. 1069  (1983)  (finding  no Bruton  violation  where
                                                    

codefendant's statement  was  not "powerfully  incriminating.").   Not

only did  Fitzgerald not  confess guilt, he  in no manner  admitted to
                                 

knowledge of Barnett's guilt.  Thus, Fitzgerald's admissions  to Lemon
                      

inculpated neither Barnett nor Fitzgerald.14

                    

gerald in the guise of reciting Lemon's investigative efforts.

     14Whatever prejudice might otherwise have resulted from the joint
trial  was minimized by precautions the district court took to forfend
against  it.   After  the pretrial  severance  motion was  denied, the
government  stipulated that any  testimony relating post-arrest state-
ments by  Fitzgerald would not refer  to Barnett by name  and the dis-
trict court  firmly admonished against  "any mention of  [Barnett]" in
connection with Fitzgerald's statements.
    Barnett nevertheless  maintains that  the court  committed revers-
ible  error by failing to instruct the jury that Fitzgerald's extraju-
dicial  statements were  not admissible  against Barnett,  even though
Barnett did not request a limiting instruction, either  at the time of
the ruling or at the time of the final jury charge, and even though he
did not object to the charge.  The claim must be deemed waived, United
                                                                      
States  v. Mateos-Sanchez, 864 F.2d  232, 238 (1st  Cir. 1988); United
                                                                      

                                  26

    Barnett  submits that  severance  was  warranted, nonetheless,  to

avoid the  cumulative prejudice from Fitzgerald's extrajudicial state-

ments  and  the  testimony  of Sheryl  Fitzgerald.15    The  severance

ruling  is reviewable for abuse  of discretion, reversible  only if it

"'deprived  defendant of a fair  trial, resulting in  a miscarriage of

justice.'"  United States v. Tejeda, 974 F.2d 210, 219 (1st Cir. 1992)
                                   

(quoting  United States  v.  McLaughlin, 957  F.2d  12, 18  (1st  Cir.
                                       

1992)); see  also United States  v. Martinez, 922  F.2d 914, 922  (1st
                                            

Cir.  1991) (severance  is committed  to the  sound discretion  of the

trial  judge, reversible only on a  showing of manifest abuse).  While

incidental prejudice is sometimes unavoidable in a joint trial, only a

                    

States v. Rawwad, 807 F.2d 294, 296 (1st Cir. 1986), cert. denied, 482
                                                                 
U.S.  909 (1987),  especially since  it seems  highly likely  that the
trial court would have viewed it as a reasonable tactical decision for
defense counsel  to refrain  from requesting an  instruction recalling
the  jury's attention to Lemon's  testimony.  "We  have been extremely
reluctant  'to increase  the heavy  burdens  already imposed  on trial
judges  in criminal cases' by  mandating that the  district courts act
sua sponte  to override seemingly  plausible strategic choices  on the
          
part of counselled defendants."  United States v. De La Cruz, 902 F.2d
                                                            
121, 124 (1st Cir.  1990) (quoting United States v.  Reveron Martinez,
                                                                     
836  F.2d 684, 687  (1st Cir. 1988)).   Furthermore,  we are confident
that there  was no plain error.  The absence of a limiting instruction
did not "seriously affect the fundamental fairness and basic integrity
of the proceedings," United States v.  Griffin, 818 F.2d 97, 100  (1st
                                              
Cir.), cert. denied, 484 U.S. 844 (1987).
                   

     15Barnett identifies two aspects of Sheryl Fitzgerald's testimony
as  especially prejudicial:   (1) that Barnett  entered the Fitzgerald
house  several times  on May 30, leaving  with clear  plastic sandwich
bags in his possession  on one occasion; and  (2) that, after  Barnett
left on  the evening of  May 30, she  found a  piece of paper  bearing
handwriting different than her  husband's, and gave it to  her husband
to deliver to Barnett.  Barnett does not mention, in  this connection,
some  of Sheryl Fitzgerald's other testimony.  For example, she testi-
fied that she rented the trailer to Barnett.

                                  27

strong   showing  of  substantial  prejudice  will  warrant  reversal.

McLaughlin, 957 F.2d at 18.
          

    The "heavy burden" of demonstrating the unfair prejudice  required

for reversal has not been met.  See United States v. Perkins, 926 F.2d
                                                            

1271, 1280  (1st Cir. 1991).  First, the record does not disclose that

this  issue was  preserved at  trial, as  Barnett neither  objected to

Sheryl Fitzgerald's testimony, nor  requested a limiting or cautionary

instruction.   Second, Barnett  identifies no basis  for excluding her

testimony, either  at a joint  trial or a  separate trial.   Thus, al-

though her testimony  inculpated Barnett, there  was no unfair  preju-

dice.

D.  Criminal Rule 35
                    

    Barnett  appeals  from the  dismissal  of  his  motion to  correct

sentence pursuant to  Fed. R. Crim. P. 35(a), which  sought a downward

departure due  to diminished  mental capacity.16   The district  court

                    

     16Barnett  claims that  he suffers  from short-term  memory loss.
Mental and emotional conditions generally are not grounds for downward
departure.  U.S.S.G.   5H1.3.   See United States v. Lauzon,  938 F.2d
                                                           
326, 333 (1st Cir.), cert. denied,     U.S.    , 112  U.S. 450 (1991);
                                 
United States v.  Studley, 907 F.2d 254, 257 (1st  Cir. 1990).  Never-
                         
theless, a guideline policy statement provides as follows:

    If the  defendant committed a non-violent  offense while suf-
    fering from significantly reduced mental capacity not result-
    ing from voluntary use of drugs or other intoxicants, a lower
    sentence may  be warranted  to reflect  the  extent to  which
    reduced mental capacity contributed  to the commission of the
    offense, provided that the defendant's criminal  history does
    not indicate a need for incarceration to protect the public.

U.S.S.G.   5K2.13.

                                  28

dismissed on the ground that it lacked the power to grant relief under

Rule 35(a).  

    Rule  35(a)17 expressly  empowers a  district court  to correct  a

sentence  only on remand from the court  of appeals.  United States v.
                                                                   

Carr, 932 F.2d 67,  69 (1st Cir.), cert. denied,      U.S.    , 112 S.
                                               

Ct. 112 (1991).   Rule  35(c), which permits  the sentencing court  to

correct  a sentence imposed as a result of arithmetical, technical, or

other  clear error, was not  in effect either  when the Barnett motion

was filed or  dismissed.  Moreover, in this case  we need not consider

whether the district court  had the inherent power to  correct obvious
                                                                      

sentencing errors, see United  States v. Rico, 902 F.2d  1065, 1067-68
                                             

(2d Cir.), cert. denied,      U.S.    , 111 S. Ct. 352  (1990); United
                                                                      

States  v. Cook, 890 F.2d 672, 674-75  (4th Cir. 1989); see also Carr,
                                                                     

932 F.2d at 70-71, since there were  none.  As the sentence imposed on

Barnett  was in  no respect  unlawful or  unreasonable, the  motion to

reconsider was properly dismissed.

                    

     17Federal Rule of Criminal Procedure 35(a) provides:

    The  court shall  correct  a sentence  that is  determined on
                                                                 
    appeal under 18 U.S.C. 3742 to have been imposed in violation
          
    of law, to  have been  imposed as  a result  of an  incorrect
    application  of  the  sentencing  guidelines, or  to  be  un-
    reasonable, upon remand of the case to the court   
                           
    (1)  for imposition of a sentence in accord with the findings
    of the court of appeals; or
    (2) for  further sentencing  proceedings if, after  such pro-
    ceedings, the court determines that the original sentence was
    incorrect.

Fed. R. Crim. P. 35(a) (emphasis added).

                                  29

E.  Outrageous Government Conduct
                                 

    Barnett claims that the indictment  should have been  dismissed on

due process grounds,  since Agent  Kelly's sale of  hydriodic acid  to

Jordan  constituted outrageous  government conduct.   Law  enforcement

conduct violates the  Due Process Clause of the  Fifth Amendment if it

results in a denial of "'fundamental fairness, shocking to the univer-

sal  sense of justice.'"  United States  v. Russell, 411 U.S. 423, 432
                                                   

(1973)  (quoting Kinsella v. United States ex rel. Singleton, 361 U.S.
                                                            

234, 246  (1960)).  See also  United States v. Panitz,  907 F.2d 1267,
                                                     

1272  (1st Cir. 1990) ("The Supreme  Court has not foreclosed the pos-

sibility  that the  government's  active participation  in a  criminal

venture may  be of so  shocking a nature  as to violate  a defendant's

right  to due process,  notwithstanding the defendant's predisposition

to commit the crime").  We find no due process violation.

    Because drug conspiracies are  notoriously difficult to penetrate,

courts  consistently have  allowed greater  government  involvement in

drug-crime investigations.  Panitz, 907 F.2d at 1273.  Law enforcement
                                  

infiltration of drug rings,  and even limited investigative participa-

tion  in  their  unlawful  operations, do  not  constitute  outrageous

government conduct violative  of due  process.  Russell,  411 U.S.  at
                                                       

432.

    Although Agent Kelly sold Jordan a  precursor chemical which is an

integral  methamphetamine component,  the government  was  neither the

conspirators' sole source (hydriodic  acid obtained from other sources

was seized in the  warehouse search), nor did the  government initiate

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the criminal conduct.   Jordan told Agent Kelly that  Barnett had been

producing methamphetamine for ten years.  Other evidence revealed that

Jordan and Barnett  had manufactured  eight to ten  pounds of  metham-

phetamine  in 1989.   The sale  of hydriodic  acid to  Jordan in these

circumstances was a permissible investigative effort to infiltrate the

suspected drug-related conspiracy.  The district court properly denied

the motion to dismiss on due process grounds.

F.  Cumulative Error
                    

    Finally, as  most assignments  of error were  baseless, we  reject

Barnett's  contention that the cumulative effect of the many errors he

alleges required reversal on  due process grounds.  We are well satis-

fied that Barnett received due process:   "[T]he Constitution entitles

a criminal defendant to a fair trial, not a perfect one."  Delaware v.
                                                                   

Van Arsdall, 475 U.S. 673, 681 (1986).  
           

    The sentence of appellant Jordan  and the conviction  and sentence
                                                                      

of appellant Barnett are affirmed.
                                 

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