209 F.3d 652 (7th Cir. 2000)
UNITED STATES OF AMERICA,    Plaintiff-Appellee,v.KIYMIKO A. HARDIN, KEITH L. ROBINSON,  GREGORY SALLIS, and JOELL JORDAN,   Defendants-Appellants.
Nos. 99-1175, 99-1285, 99-1224, and 99-1261.
In the  United States Court of Appeals  For the Seventh Circuit
Argued January 7, 2000Decided March 30, 2000

Appeals from the United States District Court  for the Eastern District of Wisconsin.  No. 98-CR-60--Thomas J. Curran, Judge. [Copyrighted Material Omitted]
Before POSNER, Chief Judge, and ROVNER and EVANS,  Circuit Judges.
EVANS, Circuit Judge.


1
In addition to some  garden-variety issues, the appeal from this  multiweek, multidefendant drug trafficking trial  presents an interesting question about whether a  provision in the continuing criminal enterprise  statute is a mere penalty enhancement or an  element of the crime. On which side of the line  the item falls is rather important, of course. An  element of the crime must be charged in the  indictment, submitted to a jury, and proved  beyond a reasonable doubt. See, e.g., Jones v.  United States, 119 S. Ct. 1215, 1219 (1999). A  sentencing factor, by contrast, need not be set  forth in the indictment, may be decided by the  judge, and must be proved only by a preponderance  of the evidence or perhaps in extreme  circumstances by clear and convincing evidence.  See, e.g., Almendarez-Torres v. United States,  118 S. Ct. 1219, 1223 (1998); United States v.  Watts, 117 S. Ct. 633, 637 (1997).


2
The Supreme Court held in Jones that  subsections of the federal carjacking statute, 18  U.S.C. sec. 2119, that allow steeper penalties if  the crime resulted in serious bodily injury or  death must be treated as distinct elements of the  crime rather than as sentencing factors. 119 S.  Ct. at 1228. Jones has spawned a flurry of  challenges to other criminal laws from defendants  across the country who argue that statutory  provisions long assumed to be sentencing factors  actually are elements. A handful of these appeals  have been successful,1 but most have not.2


3
In this case Keith L. Robinson brings a Jones-  inspired attack on 21 U.S.C. sec. 848, the  continuing criminal enterprise (CCE) statute. A  jury found that Robinson had engaged in a  continuing criminal enterprise as defined in sec.  848(c). In the district court, Judge Curran  determined that Robinson satisfied sec. 848(b)(1)  as a principal organizer and leader of the  enterprise and sec. 848(b)(2)(A) because he was  involved in trafficking at least 10 kilograms of  crack cocaine (well in excess of the quantity  required to trigger the statute). As called for  by sec. 848(b), Judge Curran sentenced Robinson  to life in prison.


4
Robinson, one of the four appellants in this  case, argues that sec. 848(b)'s criteria  regarding principal involvement and drug quantity  constitute elements of the crime and are not mere  sentencing factors within the purview of the  judge. Though decisions on whether Jones applies  to other laws are popping up every few weeks in  the Federal Reporter, as of this writing this  appears to be the first Jones challenge to the  CCE statute.


5
Because this circuit previously said that sec.  848(b) is a sentencing enhancement provision,  United States v. Kramer, 955 F.2d 479, 484 n.4  (7th Cir. 1992), and because Jones did not come  down until after Robinson's trial and sentencing,  it is no surprise that he did not mention this  issue earlier. Nonetheless, by failing to raise  the argument in the district court, Robinson can succeed on appeal only if (1) there was error,  (2) the trial court's error was plain at the time  of the appeal, and (3) the error affected  Robinson's substantial rights. See United States  v. Ross, 77 F.3d 1525, 1538-39 (7th Cir. 1996).


6
Whether a statutory provision constitutes a  substantive element of the offense or a  sentencing factor generally depends on what  Congress intended; what Congress intended is  determined by examining the statute's language,  structure, subject matter, context, and history.  See Almendarez-Torres, 118 S. Ct. at 1223.


7
The relevant portions of 21 U.S.C. sec. 848  read as follows:


8
(a) Penalties; forfeitures.  Any person who  engages in a continuing criminal enterprise shall  be sentenced to a term of imprisonment which may  not be less than 20 years and which may be up to  life imprisonment . . . except that if any person  engages in such activity after one or more prior  convictions of him under this section have become  final, he shall be sentenced to a term of  imprisonment which may not be less than 30 years  and which may be up to life imprisonment . . . .


9
(b) Life imprisonment for engaging in continuing  criminal enterprise.  Any person who engages in  a continuing criminal enterprise shall be  imprisoned for life and fined in accordance with  subsection (a), if--


10
(1) such person is the principal administrator,  organizer, or leader of the enterprise or is one  of several such principal administrators,  organizers, or leaders; and


11
(2)(A) the violation referred to in subsection  (c)(1) involved at least  300 times the quantity of a substance described  in subsection 401(b)(1)(B) of this Act [21 USCS  sec. 841(b)(1)(B)], or


12
(B) the enterprise, or any other enterprise in  which the defendant was the principal or one of  several principal administrators, organizers, or  leaders, received $10 million dollars in gross  receipts during any twelve-month period of its  existence for the manufacture, importation, or  distribution of a substance described in section  401(b)(1)(B) of this Act [21 USCS sec.  841(b)(1)(B)].


13
(c) "Continuing criminal enterprise" defined.   For purposes of subsection (a), a person is  engaged in a continuing criminal enterprise if--


14
(1) he violates any provision of this title or  title III the punishment for which is a felony,  and


15
(2) such violation is a part of a continuing  series of violations of this title or title III--


16
(A) which are undertaken by such person in  concert with five or more other persons with  respect to whom such person occupies a position  of organizer, a supervisory position, or any  other position of management, and


17
(B) from which such person obtains substantial  income or resources.


18
The language of sec. 848(b) suggests that  Congress intended it to be a sentencing  enhancement, not an element of the crime. First,  the title of the subsection--"Life imprisonment  for engaging in continuing criminal enterprise"--  emphasizes sentencing. Second, the body of the  subsection does not define what it means to  engage "in a continuing criminal enterprise."  That definition is found in sec. 848(c), where  Congress was most likely to have placed all the  elements. Third, the phrase "shall be imprisoned"  typically divides the (preceding) elements of the  crime from the (subsequent) sentencing factors.  What Robinson claims are elements fall on the  wrong side of that boundary phrase.


19
The structure of sec. 848(b) indicates that it  is intended to be a sentencing enhancement, not  an element. Subsection (c) defines the crime.  Subsection (a) lays out the basic sentencing  range (20 years to life) and adds a sentencing  enhancement (30 years to life) if the defendant  has a prior drug conviction. Likewise, subsection  (b) adds a sentencing enhancement (life) if the  defendant was a key player in the CCE and if the  CCE involved lots of drugs or a lot of profits.  Reading subsections (a) and (b) as both  sentencing provisions that rely on subsection (c)  makes more sense than reading subsection (a) to  rely in full on subsection (c), but reading  subsection (b) to rely in part on subsection (c)  and to stand in part on its own. This is  bolstered by the language in sec. 848(b) that  mirrors the wording in sec. 848(a). Subsection  (a) begins: "Any person who engages in a  continuing criminal enterprise shall be sentenced  . . . ." Subsection (b) begins: "Any person who  engages in a continuing criminal enterprise shall  be imprisoned . . . ." This identical language  suggests that, like subsection (a), subsection  (b) is a penalty provision.


20
The subject matter of sec. 848(b) tilts in  favor of a sentencing factor. Subsection (b) does  not criminalize additional types of conduct, but  mandates the maximum sentence for defendants  whose behavior is an aggravated form of the basic  conduct specified in subsection (c). A bigger  penalty for someone who has a bigger role in a  scheme involving a big amount of illegal drugs or  a big amount of illicit profits looks more like  a sentencing enhancement than a distinct  substantive element. (At issue in Robinson's  mandatory life sentence are level of involvement  and quantity of drugs; the alternative factor in  sec. 848(b)(2)(B) regarding the size of profits  is not in play.)


21
Level of culpability has long been considered a  sentencing factor. Two individuals convicted of  the same crime generally will not receive  identical sentences if one was more deeply  enmeshed in the illegality than the other. "'Role  in the offense' is a traditional determination,  made in every sentencing, which long antedates  the Guidelines." United States v. Schultz, 14  F.3d 1093, 1099 (6th Cir. 1994). The sentencing  guidelines incorporate that tradition, bumping up  the sentence of a defendant who played an  aggravated role in the offense, see U.S.S.G. sec.  3B1.1, and shaving off a bit of time for a  defendant who played a minimal part, see U.S.S.G.  sec. 3B1.2. Surely the sort of sentencing factor  properly created through congressional delegation  to the Sentencing Commission, see Mistretta v.  United States, 488 U.S. 361 (1989), also may be  imposed directly by Congress.


22
Drug quantity also is a traditional sentencing  factor. Under 21 U.S.C. sec. 841(b), the bigger  the amount of illegal drugs, the bigger the  penalty. "This court has held consistently that  the quantity of drugs involved in a narcotics  case does not constitute a substantive element of  the drug offense." United States v. Trujillo, 959  F.2d 1377, 1381 (7th Cir. 1992). Were we to view  the situation differently, we would, as noted  last week, be embarking on a path that would lead  to a "dubious destination." United States v.  Jackson, 207 F.3d 910 (7th Cir. March 23,  2000).


23
The context of sec. 848(b) also supports the  view that it is a penalty enhancement, not a  substantive element. As explained in sec. 848(a),  any defendant convicted on a CCE charge must be  sentenced from 20 years to life in prison.  Subsection (b) does not expose a defendant to  greater punishment than he already might have  received, but makes the existing maximum sentence  the minimum sentence, as well, for a defendant  who played an aggravated role in the CCE. The  Supreme Court has sent mixed signals on whether  a greater danger is posed by a provision that  increases the mandatory minimum sentence or by a  provision that increases the possible maximum  sentence. Compare Almendarez-Torres, 118 S. Ct.  at 1231 ("the risk of unfairness to a particular  defendant is no less, and may well be greater,  when a mandatory minimum sentence, rather than a  permissive maximum sentence, is at issue"), with  McMillan v. Pennsylvania, 477 U.S. 79, 88 (1986)  (defendants' argument that a provision is really  an element of the offense "would have at least  more superficial appeal" if the measure in  question "exposed them to greater or additional  punishment"). The bottom line is that the Supreme  Court has treated both types of laws as  sentencing factors, including measures like this  one that trigger a minimum sentence that falls  within the range already laid out in the statute.  Id. at 87-93, 106 S.Ct.2411.


24
The legislative history offers further evidence  that Congress meant sec. 848(b) to be a penalty  enhancement. When added in 1986 to sec. 848,  which did not originally contain a mandatory life  sentence, subsection (b) was titled "Continuing  Criminal Enterprise Enhanced Penalties." Anti-  Drug Abuse Act of 1986, Pub. L. No. 99-570, sec.  1253, 100 Stat. 3207. Lawmakers characterized the  legislation as providing tough new penalties for  drug dealers, not as creating new crimes. See,  e.g., 132 Cong. Rec. 26834 (1986) (statement of  Sen. Nunn) ("[t]he bill strengthens the penalties  for major drug traffickers"); 132 Cong. Rec.  26835 (1986) (statement of Sen. Trible) ("it  substantially increases the criminal penalties  for drug dealers . . . . It is time for more  vigorous law enforcement and for tougher  penalties that will put major drug traffickers  out of business forever. For that reason, I  introduced legislation to impose life  imprisonment on those convicted of continuing  criminal enterprises involving large-scale drug  trafficking"); 132 Cong. Rec. 31417 (1986)  (statement of Sen. Byrd) ("it contains  significantly enhanced penalties for drug crimes.  It requires minimum mandatory sentences, with no  parole, no probation. And it provides for life  sentences for major criminals--the drug 'king  pins'").


25
Robinson's argument relies on language from a  footnote in Jones that says, "[U]nder the Due  Process Clause of the Fifth Amendment and the  notice and jury trial guarantees of the Sixth  Amendment, any fact (other than prior conviction)  that increases the maximum penalty for a crime  must be charged in an indictment, submitted to a  jury, and proven beyond a reasonable doubt." 119  S. Ct. at 1224 n.6. Following this phrase  literally would produce indictments that are even  more complex, make jury verdicts even more  exhaustive, further constrict what little  sentencing discretion is left to today's trial  judges, transform the U.S. Code and the  sentencing guidelines, and erase fresh Supreme  Court precedent that allows sentencing courts to  consider not only defendant conduct that the jury  did not decide upon but also defendant conduct of  which the defendant was acquitted, see Watts, 117  S. Ct. at 638.


26
Though we do not doubt the Supreme Court's  willingness to undertake revolutionary change, we  are skeptical that the Court would announce such  an important legal metamorphosis halfway through  a footnote halfway through an opinion that  consists mostly of a fact-intensive analysis of  a specific statute and that in the end punts on  whether Congress meant the provision in question  to be a sentencing factor or an element, but to  play it safe treats the provision as an element.  Other passages in Jones cast doubt on whether the  footnote really means what it says. "It is not,  of course, that anyone today would claim that  every fact with a bearing on sentencing must be  found by a jury; we have resolved that general  issue and have no intention of questioning its  resolution." 119 S. Ct. at 1226. "[O]ur decision  today does not announce any new principle of  constitutional law." 119 S. Ct. at 1228 n.11.


27
Most other circuits have not adopted the  breathtakingly sweeping interpretation of Jones  that Robinson recommends. The Eleventh Circuit  noted that "if any factor that increases the  maximum penalty amounts to an element of the  crime, the Court did not need to bother with  determining whether or not Congress considered it  an element." Hester, 199 F3.d at 1292. Consequently, Hester concluded that the Jones  footnote applies only when a statute and its  legislative history are unclear. Id. The Tenth  Circuit called Jones "exceedingly narrow" and  cabined its holding to the federal carjacking  statute only. McGuire, 200 F.3d at 673. The  D.C. Circuit said "[t]hat the Supreme Court had  doubts about the constitutionality of the  carjacking statute, doubts that it never had to  resolve, is simply too thin a reed" to depart  from prior circuit decisions interpreting a  different statute as a sentencing factor.  Williams, 194 F.3d at 105-06.


28
Unless the Supreme Court clarifies that its  holding in Jones really is as broad as what  Robinson urges, we are inclined not to turn the  criminal justice system upside down, but rather  join these circuits' more cautious reading of  that decision. We reject Robinson's suggestions  that sec. 848(b) contains a sprinkle of  sentencing factor and a dash of definition of the  elements. Instead, we hold that sec. 848(b) does  not contain substantive elements that must be  charged in the indictment, submitted to the jury,  and proven beyond a reasonable doubt, but rather  embodies a sentencing enhancement that is within  the purview of the judge. In short, there was no  error here, plain or otherwise.


29
Even if the Jones footnote is taken at face  value, Robinson would not be saved. The footnote  says any fact "that increases the maximum penalty  for a crime" must be in the indictment, go to the  jury, and satisfy proof beyond a reasonable  doubt. As discussed earlier, sec. 848(b) does not  increase the maximum penalty for a CCE  conviction, but rather imposes a mandatory  minimum penalty within the sentencing range that  is already outlined.


30
Furthermore, even if our analysis of sec.  848(b) is off the mark and Robinson's CCE  conviction is negated, he would spend life in  prison anyway. The government would reinstate his  conspiracy conviction, where his offense level of  48 would draw an automatic life sentence under  the sentencing guidelines. Also, Robinson already  was sentenced to life in prison on drug counts 3,  4, and 5.


31
A few loose ends regarding Robinson's CCE  conviction remain. The first is whether Jones  means that the drug quantities in 21 U.S.C. sec.  841(b) are elements rather than sentencing  factors, a question we already considered and  answered to the contrary in Jackson. The second  loose end involves the CCE jury instructions,  where Judge Curran told the jury that it must  unanimously agree that Robinson participated in  two or more violations of the federal narcotics  law. Though, at the time, Judge Curran was  correctly stating the law of the circuit, the  Supreme Court subsequently ruled that the jury  must unanimously agree on each of the specific,  individual violations that comprise the CCE's  "continuing series of violations." Richardson v.  United States, 119 S. Ct. 1707 (1999). The Court  also hinted that at least three violations might  be required. Id. at 1710. The Supreme Court also  recently held, however, that Federal Rule of  Criminal Procedure 52(a)'s harmless error  analysis applies to a jury instruction that omits  an element of the offense. Neder v. United  States, 119 S. Ct. 1827 (1999). We must decide  whether it is "clear beyond a reasonable doubt  that a rational jury would have found the  defendant guilty absent the error." Id. at 1838.  By unanimously finding Robinson guilty of the  drug offenses outlined in counts 3-6, the jury  unanimously agreed on four specific, individual  predicate felonies that made up the continuing  series of violations required for a CCE  conviction. The retrospective error in jury  instructions was therefore harmless.


32
The third loose end is Robinson's claim that  the jury also should have been told that it must  unanimously agree on the identity of the "five or  more other persons" with whom he was acting in  concert. Robinson "acknowledges this is a  difficult argument" and then does little to  elaborate on it. Undeveloped arguments are  waived. See JTC Petroleum Co. v. Piasa Motor Fuels, Inc., 190 F.3d 775, 780-81 (7th Cir.  1999). Regardless, the Supreme Court said that  the "five or more persons" provision is  significantly different from the "continuing  series of violations" provision and suggested  that there was no unanimity requirement for the  former. Richardson, 119 S. Ct. at 1713. We have  held that the jury is not required to agree on  the identity of the five individuals who a  defendant managed or supervised. United States v.  Gibbs, 61 F.3d 536, 538 (7th Cir. 1995). That law  stands, and so does Robinson's CCE conviction and  life sentence under sec. 848(b).


33
We turn now to the raft of more familiar  complaints raised by Robinson and his three  appellate cohorts.


34
This appeal stems from the prosecution of a  drug ring that moved large amounts of crack  cocaine, powder cocaine, heroin, and marijuana  from Los Angeles to Milwaukee, Minneapolis, and  other cities across the country, where the drugs  were sold. Fifteen individuals were indicted: two  remained at large when this trial took place,  nine pleaded guilty, and four went to trial. The  trial, which lasted more than 2 weeks, ended when  the jury found all four guilty on all counts. In  addition to the CCE conviction, Robinson was  convicted of conspiracy to possess and distribute  crack cocaine, three counts of possession and  distribution of crack cocaine, one count of  possession and distribution of cocaine, and six  other counts mostly dealing with firearms  violations and money laundering. Gregory D.  Sallis was convicted of conspiracy, one count of  possession and distribution of crack cocaine, and  one count of interstate travel in aid of a  racketeering enterprise. Joell Jordan was  convicted of conspiracy and five counts of using  a communication facility to facilitate a drug  conspiracy. Kiymiko A. Hardin was convicted of  the drug conspiracy. As noted earlier, Robinson  received a life sentence. Sallis was sentenced to  360 months in prison, Jordan to 168 months, and  Hardin to 120 months.


35
Robinson and Sallis both challenge the  sufficiency of the evidence against them. An  insufficiency of the evidence argument is an  uphill fight. United States v. Bradley, 165 F.3d  594, 595 (7th Cir. 1999). We do not second-guess  the jury's weighing of the evidence or its  assessment of the credibility of witnesses. See  United States v. Hach, 162 F.3d 937, 942 (7th  Cir. 1998). We affirm if, after viewing the  evidence in the light most favorable to the  prosecution, we find that a rational trier of  fact could have found the essential elements of  the crime beyond a reasonable doubt. Id.


36
In an attack on his conspiracy conviction,  Sallis concedes that he bought and sold drugs but  distances himself from Robinson's particular  outfit. What distinguishes a conspiracy from an  agreement between a buyer and seller is that a  conspiracy involves a further, often implicit,  understanding between the buyer and seller,  usually regarding the subsequent distribution of  the drugs. See United States v. Clay, 37 F.3d  338, 341 (7th Cir. 1994). Signs of a conspiracy  include a lengthy affiliation, an established  method of payment, standardized transactions, a  demonstrated level of mutual trust, and a seller  who knows about and has a stake in the buyer's  drug business. See United States v. Menting, 166  F.3d 923, 928 (7th Cir. 1999).


37
The evidence indicated that Sallis was not the  independent agent he claims to be. Tresa  McCormick, a seller in the organization,  testified that at Robinson's direction she picked  up her drugs on several occasions from Sallis,  whom she saw packaging a large amount of crack.  Another seller, Glen Huley, said that he and  Sallis sold drugs that belonged to the  organization's leaders--Robinson, Charles  Henderson, and Nelson James--and that they would  not have to pay for the drugs up front but could  sell the drugs and return later with the profits.  Larry Tender, one of Robinson's main operatives,  testified that he put up couriers in an apartment  after getting the keys to the apartment from  Sallis. Eugene Ward said on two occasions when he  bought crack from Robinson that Robinson was  accompanied by Sallis. Katrina Louis, a courier,  recounted that Sallis helped strap her with a  belt of money that she transported from Milwaukee  to Los Angeles. This evidence demonstrates that  Sallis was more than a mere customer of  Robinson's but, rather, had an ongoing, regular,  integral role in the drug organization.


38
Robinson on counts 3-5 and Sallis on counts 1,  3, and 12 contend that the evidence identifying  the particular drug involved as crack cocaine  fell short. The defendants brand the witnesses  who testified in this case as, in so many words,  lying scumbag drug dealers who cannot be trusted  because they got a break for cooperating.  Unsavory characters might not make ideal  witnesses, but in a drug trial the prosecution  generally does not have the luxury of drawing its  roster of witnesses from the College of  Cardinals. It is not for an appellate panel to  second-guess the jury's assessments of the  credibility of witnesses. United States v.  Griffin, 194 F.3d 808, 817 (7th Cir. 1999).


39
The defendants argue that the government failed  to prove that the controlled substance involved  in this case was indeed crack cocaine. We reject  this claim. As we have observed, the people who  transport, cook, cut up, bag, and sell crack are  the sort of people who tend to know what crack  is. See Bradley, 165 F.3d at 596 ("those who  smoke, buy, or sell this stuff are the real  experts on what is crack"). And here, numerous  witnesses identified Robinson's organization as  dealing primarily in crack (cocaine base)  cocaine. Courier Sharyea Jackson testified that  she saw cocaine being cooked up prior to the  drugs being packaged and taped to her body for  transport from Los Angeles to Milwaukee. Courier  Kimberly Jones said she saw a "big old square  rock" being cooked before she smuggled the drugs  beneath her clothes from Los Angeles to  Milwaukee. Courier Jacquitta Brooks said the  package she delivered contained a big, hard,  cream-colored block that was cut into small balls  after she made her delivery in Milwaukee. Eugene  Ward admitted buying crack, as opposed to powder  cocaine, from Robinson and then selling it.


40
Several witnesses were particularly persuasive  in their understanding of what distinguishes  crack cocaine from cocaine powder. Lamont Nelson,  a Minneapolis drug dealer, described a visit from  Robinson in which the two cooked half a kilogram  of white powdery cocaine into crack cocaine,  which looks like rock and can be smoked. Nelson  explained that the crack cocaine product weighs  more than the original cocaine powder because,  during the process, baking soda is added using a  blender. Glen Huley, who admitted helping to cook  cocaine powder into crack, clarified that by  "cocaine base" he meant the "rock form substance  of cocaine." He, too, described the process of  taking the powder form of cocaine, adding baking  soda, cooking it on a stove, and producing the  rock form of cocaine. Larry Tender, who helped  weigh, bag, and sell the drugs, said that what he  would refer to on the street as "crack" he  described as "cocaine base" during the trial  because he didn't think the jury members would  "understand what crack is." And Tresa McCormick,  who sold crack for Robinson for $800 an ounce,  recounted how she weighed and packaged crack  after first breaking it apart with her hands or  with a hammer. She explained that crack is  cocaine that is "cooked like with baking soda to  make a hard rocky like substance, so it's like  smokable. Get you a little higher than regular  cocaine would."


41
We doubt a lab technician could define crack  any more cogently or concisely. Robinson and  Sallis complain that none of these witnesses  testified to ever having used or tasted the crack  themselves. But a cashier at Jewel doesn't have  to bite off a piece of the customer's broccoli to  know which vegetable she is ringing up. The  identity of a controlled substance may be proved  by circumstantial evidence, such as the purchase  price, the secrecy of sales, and familiarity with  the drug. See United States v. Dominguez, 992  F.2d 678, 681 (7th Cir. 1993); United States v.  Marshall, 985 F.2d 901, 905 (7th Cir. 1993).  Despite the lack of scientific evidence, a  rational jury could have easily concluded from  the secrecy of the transportation process, the  prices charged, and the witnesses' firsthand  descriptions of cooking a white powdery substance  into rocks that the substance involved was crack  cocaine and not, as Sallis' brief rhetorically  suggests, rock salt.


42
In finding Robinson guilty of the specific drug  charges in counts 3-5 and Sallis guilty on count  3, the jury obviously determined that the drug  involved was crack cocaine. Because of the  precision of the indictment, however, we also  believe that the jury found in the context of the  conspiracy charge in count 1 that the drug  involved was crack cocaine. This scuttles the  sentencing complaints of Hardin and Jordan, as  well as of Robinson and Sallis, all of whom seek  resentencing on the ground that there was an  inadequate basis to determine that crack was the  controlled substance involved in this conspiracy.


43
This is not a case like Edwards v. United  States, 118 S. Ct. 1475 (1998), where the jury  found the defendant guilty of a conspiracy  involving cocaine or cocaine base (i.e., crack)  and then at sentencing the judge determined that  crack was involved and imposed the resulting  harsher penalties. Here, the first count of the  indictment specifically charged the defendants  with conspiring to distribute and possess with  intent to distribute "controlled substances,  specifically, in excess of fifty grams of cocaine  base, commonly known as 'crack' cocaine."  Granted, the jurors were instructed that the only  two elements they needed to find beyond a  reasonable doubt to convict the defendants on  this count were that the conspiracy existed and  that the particular defendant knowingly and  intentionally became a member of the conspiracy.  The jurors also were instructed, though, that if  they found the defendant(s) guilty of a  conspiracy, it had to be the conspiracy charged  in count 1 of the indictment. In finding the  defendants guilty on count 1, the jury therefore  found the defendants guilty of trafficking  "cocaine base, commonly known as 'crack'  cocaine." And if the jury found all four  defendants guilty beyond a reasonable doubt of  conspiring to deal crack cocaine, then surely  Judge Curran was on solid ground in deciding by  a preponderance of the evidence that the  controlled substance was crack cocaine and in  sentencing the defendants accordingly.


44
On a related issue, Sallis contests the  quantity of drugs that served as the basis for  his sentence. Because he did not raise his  objection at sentencing, we review for plain  error Judge Curran's decision to hold him  responsible for at least 1.5 kilograms of crack.  United States v. Hardamon, 188 F.3d 843, 848-49  (7th Cir. 1999). It was not plain error for Judge  Curran to adopt the presentence report's  recommendation that the weight of the crack  exceeded 1.5 kilograms. See United States v.  Vargas, 16 F.3d 155, 159 (7th Cir. 1994). As  discussed earlier in assessing Sallis'  sufficiency of the evidence argument, there was  plenty of testimony from multiple witnesses that  Sallis was deeply involved in this drug ring that  was moving large quantities of crack.


45
Moving on to the next issue, Robinson wants his  convictions reversed because Sallis' trial  counsel twice mentioned during closing arguments  that Robinson had not testified. Pointing out a  defendant's exercise of his Fifth Amendment right  not to be a witness against himself is thought to  compromise the right and therefore is forbidden.  Griffin v. California, 380 U.S. 609, 615 (1965).  A conviction is reversed, however, only if the  reference was not harmless. United States v.  Cotnam, 88 F.3d 487, 499-500 (7th Cir. 1996).  Even though the prosecution is not at fault when  a codefendant's attorney improperly comments on  another defendant's failure to testify, as was  the case here, the same harmless error standard  controls. See United States v. Alpern, 564 F.2d  755, 761-62 (7th Cir. 1977); United States v.  Hutul, 416 F.2d 607, 621-22 (7th Cir. 1969).


46
Sallis' trial counsel first referred to  Robinson's failure to testify while discussing  count 12 of the indictment, an interstate travel  charge under 18 U.S.C. sec. 1952(a)(3) against  Sallis, Robinson, and Denise Betts-Guignard. He  said:


47
And you have to think about the testimony that  came in about that. And essentially, we didn't  hear from Keith Robinson, Denise Betts-Guignard  or Gregory Sallis, so we have to look at other  people's testimony to determine what happened on  that day . . . . [T]he main person who testified  about that was Glen Huley. If you think back on  Mr. Huley's testimony, and, again, I'm not going  to belabor the fact that he cut a deal with the  government, that he was proven to have lied  repeatedly, that he lived a dishonest lifestyle  before he came into this courtroom. All of that  is apparent to you.


48
A few moments later, Sallis' lawyer discussed  count 3 of the indictment, a drug charge against  Sallis, Robinson, Nelson James, and Beverly  Hendrix. He said:


49
[W]hat you're left with, because we haven't heard  from Robinson, James, Hendrix or Sallis, is the  evidence that the government has brought forth  through Sharyea Jackson and Kimberly Jones.


50
Robinson pins his Fifth Amendment argument on  De Luna v. United States, 308 F.2d 140 (5th Cir.  1962), where a codefendant's attorney's repeated  references to another defendant's failure to  testify resulted in a finding of prejudicial  error. In De Luna two men were on trial: Gomez  proclaimed his innocence and pointed the finger  at his codefendant (and cousin), de Luna,3 who  did not testify. At closing, Gomez's attorney  said, "[A]t least one man was honest enough and  had courage enough to take the stand and subject  himself to cross examination, and tell you the  whole story . . . . You haven't heard a word from  this man (de Luna)." Id. at 142. De Luna only  highlights how different--and innocuous--the  situation was here: Sallis' and Robinson's  defenses did not conflict. Sallis' attorney was  not casting aspersions on those who did not  testify (indeed, he noted that Sallis himself did  not testify). Sallis' lawyer merely was arguing  that there were a limited number of people who  could testify about the crimes charged and the  only witnesses who did so were unreliable. He  could have been more careful, see United States  v. Petullo, 709 F.2d 1178, 1182 (7th Cir. 1983)  ("[c]aution is certainly indicated in these  circumstances"), but his comments, viewed in the  light of all the circumstances of this trial,  were not any more than harmless to Robinson.


51
Next, all four defendants protest the admission  of evidence that Robinson and others were part of  the Crips, a Los Angeles-based gang. Robinson's  and Sallis' pretrial objection to this evidence  was overruled by Judge Curran, a decision we will  reverse only upon a showing of a clear abuse of  discretion by the judge. United States v. Butler,  71 F.3d 243, 250 (7th Cir. 1995). Gang  affiliation is relevant where the  interrelationship between people is a central  issue. United States v. Thomas, 86 F.3d 647, 652  (7th Cir. 1996). Proving that interrelationships  existed was necessary for the government to prove  the drug conspiracy of which all four defendants  were convicted. Charging a drug conspiracy that  involves gang members, however, does give the  government carte blanche to splash gang  references throughout the trial. Gang evidence  can arouse negative connotations and be unfairly  prejudicial. Id.; United States v. Irvin, 87 F.3d  860, 865 (7th Cir. 1996).


52
The government insists that the gang evidence  was necessary to show the connection between the  members of this conspiracy, particularly how the  coconspirators first got to know each other and  how Robinson kept lower-level gang members in  line. The defendants question what relevance  affiliation with a Los Angeles gang has to  activities alleged to have occurred in Milwaukee.  The defendants also argue that the references to  the Crips were prejudicial because that gang is  particularly notorious in popular lore. Naming  the Crips as the specific gang involved was  superfluous and probably should have been  avoided. See United States v. Abel, 469 U.S. 45,  54 (1984) (not naming the Aryan Brotherhood as  the gang involved was one reason why gang  reference was not unduly prejudicial). Beyond  getting various witnesses to identify other  individuals involved in this drug ring as Crips,  the prosecution did little to develop their  theory that the connections between gang members  demonstrated connections in the drug distribution  conspiracy. Nonetheless, the gang relationships  suggested that the players in this story were  linked. Cf. Irvin, 87 F.3d at 864 (gang evidence  gratuitous because conspiracy not charged and  joint venture did not need to be proved). Though  the defendants suggest the mere utterance of the  name "Crips" sent shudders down every juror's  spine, there was no insinuation at trial that the  Crips are a particularly big and bad gang.  Furthermore, in a 12-day trial involving 42  witnesses, there were only 7 references to the  Crips and 2 additional generic gang references.  Though we do not see much probative value in this  gang evidence, we also don't see great danger of  unfair prejudice. In light of the cautionary jury  instruction and the wealth of other evidence, the  admission of these scattered gang references was  not a clear abuse of discretion and--even if it  were--was harmless.


53
Finally, Sallis and Hardin say they were  prejudiced by being tried jointly with Robinson.  Sallis is bringing up this issue for the first  time on appeal; Hardin filed a pretrial severance  motion based solely on Bruton v. United States,  391 U.S. 123 (1968), grounds. Because neither  defendant has shown cause for not raising this  particular joint trial concern in the district  court, we review only for plain error. United  States v. Gio, 7 F.3d 1279, 1285 (7th Cir. 1993).


54
If it appears a defendant is prejudiced by a  joint trial, the judge may order separate trials.  Federal Rule of Criminal Procedure 14. The  defendant must show that without severance he was  unable to obtain a fair trial, not merely that  his chance of acquittal would have been higher at  a separate trial. United States v. Thornton, 197  F.3d 241, 255 (7th Cir. 1999). Joint trials are  encouraged when a group of people are charged  with participating in the same crime because the  economies of a single trial in all but the most  unusual circumstances outweigh the danger of  prejudice to the least guilty or possibly the  prejudice to all defendants because of sheer  confusion. United States v. Velasquez, 772 F.2d  1348, 1352 (7th Cir. 1985). We presume that the  jury capably sorts through the evidence and  follows the instructions, such as the one given  by Judge Curran, to give separate consideration  to each defendant. Thornton, 197 F.3d at 256. The  classic situations where failure to sever may be  prejudicial involve the admission of damaging  evidence at a joint trial that would be  inadmissible if the defendant were being tried  alone or the exclusion at a joint trial of  exculpatory evidence that would be available if  the defendant were being tried solo. Id. Sallis  and Hardin argue their situation fits the former  scenario because the bulk of the evidence in this  case pertained to Robinson, the ringleader. Joint  trials do create the danger that the little fish  will be lumped together with the big fish. See  United States v. McAnderson, 914 F.2d 934, 949  (7th Cir. 1990). Conversely, though, joint trials  might make the little fish's activities, though  criminal, appear minor in comparison and  consequently result in acquittal. See Thornton,  197 F.3d at 256.


55
Because both Sallis and Hardin were charged  with conspiracy, much of the evidence they found  objectionable in the joint trial would have been  admissible at separate trials anyway.  Conspirators are on the hook for foreseeable acts  of coconspirators that are in furtherance of the  conspiracy. See Hach, 162 F.3d at 951 (7th Cir.  1998). Sallis' perfervidly argued small fish  theory is especially hard to swallow. As shown by  our earlier discussion of his insufficiency of  the evidence argument, he was no bit player in  this drug ring.


56
Hardin's claim is more plausible and evokes  more sympathy, since she was only a low-level  courier who ended up with a mighty stiff  sentence. Nevertheless, ferrying drugs to  Milwaukee and drug money back to Los Angeles  might not be as bad as orchestrating the  business, but it is illegal and it makes one part  of the conspiracy. Larry Tender, Glen Huley, and  LaQuita Hampton all identified Hardin as a drug  courier. Tender described three occasions when he  met Hardin in Milwaukee upon her arrival from Los  Angeles to receive the packages of crack cocaine  she had transported. Sharyea Jackson testified  she and Hardin made trips to Los Angeles, each  carrying a concealed money belt. Hardin  challenges the reliability of these witnesses,  all of whom cooperated with the government and  received more lenient sentences. But credibility  is a call for the jury, not us. At any rate,  these witnesses would not have been any more or  less credible had they testified at a trial where  Hardin was being tried alone.


57
The jury found all four defendants guilty of  all counts charged, but in their next round of  deliberations reduced to $2,400 the $1 million  forfeiture sought by the government from Hardin.  By contrast, the jury imposed the $1 million  forfeiture the government sought against  Robinson, Sallis, and Jordan. A mixed verdict on  the actual charges is more telling, see Thornton,  197 F.3d at 256, but variance in a forfeiture  decision also indicates that the jury considered  the evidence against each defendant individually.  Given this factor, the cautionary instruction the  jury received, and the weight of the evidence  against both Sallis and Hardin individually, we  do not believe that it was plain error to try  them jointly with Robinson and Jordan.


58
We affirm the convictions and sentences entered  in the district court against all four  defendants.



Notes:


1
 See United States v. Terence Earl Davis, 202 F.3d 212 (4th Cir. 2000) (destruction of property or  a dwelling or destruction of property that  jeopardizes a person's life is an element in 18  U.S.C. sec. 1363); United States v. John Alvin  Davis, 184 F.3d 366, 367 (4th Cir. 1999) (great  bodily injury is an element in South Carolina law  regarding failure to stop when signaled by a law  enforcement officer); United States v. Allen, 190  F.3d 1208 (11th Cir. 1999) (intending to use  object as a weapon is an element in 18 U.S.C.  sec. 1791(d)(1)(B)); United States v. Nunez, 180  F.3d 227, 233 (5th Cir. 1999) (resisting arrest  by federal officer by more than simple assault or  with a dangerous weapon is an element in 18  U.S.C. sec. 111). See also United States v.  Chestaro, 197 F.3d 600 (2d Cir. 1999) (using a  deadly and dangerous weapon or inflicting serious  bodily injury is an element in 18 U.S.C. sec.  111(b) and therefore defendant's double jeopardy  violation claim is rejected).


2
 See United States v. Jackson, 207 F.3d 910 (7th  Cir. March 23, 2000) (quantity of drugs is a  sentencing factor in 21 U.S.C. sec. 841); United  States v. Swiney, 203 F.3d 397, 404 n.5 (6th  Cir. 2000) (same); United States v. Hester, 199  F.3d 1287, 1292 (11th Cir. 2000)  (same); United States v. Carless Jones, 194 F.3d  1178, 1183-86 (10th Cir. 1999) (same); United  States v. Williams, 194 F.3d 100, 105-07 (D.C.  Cir. 1999) (same); United States v. McGuire, 200 F.3d 668, 671-74 (10th Cir. 1999) (serious bodily  injury is a sentencing factor under U.S.S.G. sec.  2B3.1(b)(3)(B)); United States v. Cruz-Guerrero,  194 F.3d 1029 (9th Cir. 1999) (carrying a gun  during commission of a felony is a sentencing  factor in California law); United States v.  Kaluna, 192 F.3d 1188, 1196 (9th Cir. 1999)  (exception to the definition of a strike that  could prevent stiffer penalty under three-strikes  law is part of a sentencing factor in 18 U.S.C.  sec. 3559(c)(3)(A)); United States v. Eads, 191  F.3d 1206, 1214 (10th Cir. 1999) (type of firearm  is a sentencing factor in 18 U.S.C. sec.  924(c)(1)); United States v. Castillo, 179 F.3d  321, 328 (5th Cir. 1999) (same); United States v.  Baldwin, 186 F.3d 99, 102 (2d Cir.) (existence of  prior felony convictions is a sentencing factor  in 18 U.S.C. 924(e)), cert. denied, 120 S. Ct.  558 (1999); United States v. Matthews, 178 F.3d  295, 302 (5th Cir.) (involvement in a criminal  street gang is a sentencing factor in 18 U.S.C.  sec. 521), cert. denied, 120 S. Ct. 559 (1999).


3
 The caption of the case names the defendant as  Carlos Garza De Luna. In the body of the opinion,  however, he is called Carlos Garza de Luna.


