                                                        [DO NOT PUBLISH]


            IN THE UNITED STATES COURT OF APPEALS

                   FOR THE ELEVENTH CIRCUIT
                     ________________________                  FILED
                                                      U.S. COURT OF APPEALS
                            No. 09-11466                ELEVENTH CIRCUIT
                                                           AUGUST 6, 2010
                        Non-Argument Calendar
                                                             JOHN LEY
                      ________________________
                                                              CLERK

                    D. C. Docket No. 05-00002-CR-2


UNITED STATES OF AMERICA,

                                                              Plaintiff-Appellee,

                                 versus

ANDREW COX,

                                                        Defendant-Appellant.


                      ________________________

               Appeal from the United States District Court
                  for the Northern District of Georgia
                    _________________________

                            (August 6, 2010)

Before EDMONDSON, CARNES and MARCUS, Circuit Judges.
PER CURIAM:

      Andrew Cox appeals his conviction for conspiracy to manufacture

marijuana, 21 U.S.C. §§ 841(a)(1), 846. No reversible error has been shown; we

affirm.

      We first address Cox’s challenge to the district court’s denial of his motion

to suppress. We review the denial of a motion to suppress under a mixed standard

of review, examining the district court’s factual determinations for clear error and

its application of law to those facts de novo. United States v. Boyce, 351 F.3d

1102, 1105 (11th Cir. 2003). And we construe all facts in the light most favorable

to the prevailing party -- here, the government. Id.

      Cox sought to suppress evidence seized pursuant to a search warrant issued

for property located at 4050 Youngblood Drive, Union County, Georgia. United

States Forest Service (“USFS”) Agents received a call that complained of ATV

tracks running across the caller’s property and onto USFS property. The caller

also noted that he observed “strange plants” on USFS property at the end of the

ATV tracks. USFS agents investigated and discovered between 150 and 200 dead

and dying marijuana plants in starter trays. The agents followed the ATV tracks

farther and found a footpath that led to a clearing. The ATV tracks were followed




                                          2
to Youngblood Drive, a dirt road, which agents believed was county-maintained.

After traveling a short distance on Youngblood Drive, the agents noticed another

footpath. Agents observed no signs indicating they were still within USFS

property and no signs -- such as “no trespassing” signs -- indicating they were on

private property. Following the footpath up a ridge agents reached the edge of the

tree line where they observed a cleared area and a cabin, an open carport, and an

outbuilding.

      Agent Woodall wanted to inquire at the cabin about the ATV tracks that led

to the marijuana found on USFS property. To that end, he walked a direct path

from the roadbed straight to the cabin door. En route, no signage, fencing, or other

barriers restricting access were observed. What was observed, however, directly

on that route, was a large number of marijuana plants in starter trays similar to

those found on the USFS property. When no one responded to Agent Woodall’s

knock on the cabin door, Agent Woodall returned to the tree line.

      Because agents had approached the cabin after hiking from USFS property

to the tree line on a footpath, they did not know the address of the cabin or how to

reach it by car. Following the driveway, agents reached a locked gate at the

intersection of the driveway and Youngblood Drive. A gap existed next to the gate

that led the agents to believe the gate was intended to restrict access by large



                                           3
vehicles. Agents recalled no signage on or near the gate.

      A state-issued warrant was obtained for the cabin. Agents continued

surveillance of the property and commenced execution of the warrant only after

some activity was observed on the property in the vicinity of the marijuana plants.

      The district court determined that Cox had no legitimate expectation of

privacy in the Youngblood Drive property: the cabin was not titled in his name,

lacked indicia of use, and housed no personal or business items. The district court

determined further that, even if Cox could show a legitimate expectation of privacy

sufficient to support a Fourth Amendment challenge, no entry to the property

violated his Fourth Amendment rights. We agree.

      As Cox concedes, the surveillance point from which the footpath leading to

the cabin was observed did not fall within the curtilage of the cabin. See United

States v. Hatch, 931 F.2d 1478, 1480 (11th Cir. 1991) (“the special protection

accorded by the Fourth Amendment to the people in their ‘persons, houses, papers

and effects,’ is not extended to the open fields.”) (citation omitted). Cox argues

instead that the area along the footpath leading to the front of the cabin -- from

which marijuana starter plants were in plain view -- is within the protected

curtilage of the cabin such that Agent Woodall’s observations as he approached the

cabin violated his rights and tainted the warrant that issued to search the cabin.



                                           4
      To establish a legitimate expectation of privacy, a person must establish a

subjective expectation of privacy that society recognizes as legitimate. See United

States v. Smith, 459 F.3d 1276, 1290 n.14 (11th Cir. 2006). The Fourth

Amendment’s proscriptions are “not implicated by entry upon private land to

knock on a citizen’s door for legitimate police purposes unconnected with a search

of the premises.” United States v. Taylor, 458 F.3d 1201, 1204 (11th Cir. 2006).

“Absent express orders from the person in possession, an officer may walk up the

steps and knock on the front door of any man’s ‘castle,’ with the honest intent of

asking questions of the occupant thereof. Thus, officers are allowed to knock on a

residence’s door or otherwise approach the residence seeking to speak to the

inhabitants just as any private citizen may.” Id. (internal quotations and citations

omitted).

      We see no error in the district court’s factual findings and conclusion of law

that Agent Woodall’s approach to the cabin to conduct a “knock and talk” violated

no reasonable expectation of privacy. His plain view observations while properly

on the property constitute no constitutional violation; and inclusion of these

observations in the warrant affidavit do not taint the validity of the warrant issued

to search the cabin.

      Cox also argues that the district court erred by admitting his two prior



                                           5
marijuana trafficking convictions in violation of Fed.R.Evid. 404(b). We review

the district court’s Rule 404(b) rulings for an abuse of discretion. United States v.

Ellisor, 522 F.3d 1255, 1267 (11th Cir. 2008). Under Rule 404(b), evidence of

other crimes is not admissible to show proof of bad character. But it may be

admissible to prove motive, knowledge, or intent as long as the evidence is

relevant to an issue other than defendant’s character and the risk of undue

prejudice from the evidence does not outweigh substantially its probative value.

See Fed.R.Evid. 404(b); see also Fed.R.Evid. 403.

       Here, Cox’s intent was at issue because he pleaded not guilty and denied

participating in the conspiracy. United States v. Kopituk, 690 F.2d 1289, 1334

(11th Cir. 1982) (concluding that, “in the context of a conspiracy case, the mere

entry of a not guilty plea sufficiently raises the issue of intent to justify the

admissibility of extrinsic offense evidence”). And “[e]vidence of prior drug

dealings is highly probative of intent to distribute a controlled substance, as well as

involvement in a conspiracy.” United States v. Cardenas, 895 F.2d 1338, 1344

(11th Cir. 1990).

       Cox argues that the prior trafficking convictions were dissimilar to the

manufacturing or growing of marijuana and, thus, were unduly prejudicial. But the

prior convictions involved large amounts of drugs just like the instant offense; and



                                             6
the lack of similarity between the convictions does not render the evidence

substantially more prejudicial than probative. See United States v. Delgado, 56

F.3d 1357, 1366 (11th Cir. 1995) (rejecting the argument that the lack of similarity

between a large-scale drug conspiracy and a comparatively smaller, one-time drug

purchase from an undercover law enforcement officer made evidence subject to

Rule 403 exclusion). Because Cox’s prior drug convictions were highly probative

of intent and not subject to exclusion under Rule 403, the district court abused no

discretion in admitting them.

       Cox also challenges the district court’s admission of Special Agent Russell

Arthur as an expert witness under Fed.R.Evid. 702. He maintains that Arthur’s

testimony was unreliable, speculative, and unhelpful to the jury.1 We review a

district court’s ruling on the admissibility of expert testimony for an abuse of

discretion and we “defer to the district court’s ruling unless it is manifestly

erroneous.” United States v. Douglas, 489 F.3d 1117, 1124 (11th Cir. 2007).

Expert testimony must be based on reliable methodology and must be helpful to

the jury. See Fed.R.Evid. 702; United States v. Frazier, 387 F.3d 1244, 1260 (11th

Cir. 2004). The trial judge is responsible for ensuring that an expert’s testimony is

both reliable and relevant. Daubert v. Merrell Dow Pharms., Inc., 113 S.Ct. 2786,


       1
        Cox does not challenge that Arthur was qualified to testify as an expert in the field of
outdoor marijuana field manufacturing.

                                                 7
2795 (1993).

       Here, evidence showed that Arthur had worked with the USFS for 25 years,

received specialized training in outdoor marijuana grow operations, participated in

a thousand investigations involving marijuana grow operations, and interviewed

over 50 people associated with marijuana grow operations. Based on Arthur’s

extensive experience with this subject, we cannot say that the district court’s ruling

allowing Arthur to testify about the nature of marijuana grow operations was

manifestly erroneous. See United States v. Garcia, 447 F.3d 1327, 1335 (11th Cir.

2006) (there is a “well-established rule that an experienced narcotics agent may

testify as an expert to help a jury understand the significance of certain conduct or

methods of operation unique to the drug distribution business”) (internal quotations

omitted). Moreover, Arthur’s testimony assisted the jury in assessing the role

played by the co-conspirators in the marijuana grow operation, the connection

between prior marijuana trafficking and marijuana cultivation, and the role

typically played by the manager of a marijuana grow operation, which was outside

the common knowledge of the jury.2

       Now we address Cox’s challenge to the sufficiency of the evidence.



       2
         Contrary to Cox’s appellate argument, the record does not show that the government
questioned Arthur specifically about Cox’s alleged involvement in this case; instead, Arthur
testified in generalities and interpreted the evidence collected by investigative agents.

                                               8
Because Cox failed to move for a judgment of acquittal at the close of all the

evidence, “we will reverse his conviction[] only to prevent a manifest miscarriage

of justice.” United States v. Milkintas, 470 F.3d 1339, 1343 (11th Cir. 2006).

“This standard requires a finding that the evidence on a key element of the offense

is so tenuous that a conviction would be shocking.” Id. (internal quotation

omitted).

      To convict Cox of conspiracy to manufacture marijuana, the government had

to “prove beyond a reasonable doubt that there existed an agreement between two

or more persons to [manufacture marijuana] and that [Cox] knowingly and

voluntarily participated in that agreement.” United States v. Arbane, 446 F.3d

1223, 1228 (11th Cir. 2006). The government need not prove that Cox “knew all

of the detail or participated in every aspect of the conspiracy,” but instead “must

only prove that [he] knew the essential nature of the conspiracy.” United States v.

Garcia, 405 F.3d 1260, 1270 (11th Cir. 2005). “Once the existence of a conspiracy

is established, only slight evidence is necessary to connect a particular defendant to

the conspiracy.” Id.

      Here, Cox did not dispute that a conspiracy to manufacture marijuana

existed between the Hispanic workers he hired to do landscaping work on his

father’s property. He merely argued that the workers committed the offense



                                           9
without his knowledge. Thus, only slight evidence was needed to connect Cox to

the conspiracy. See id.

       And evidence showed that Cox (1) took his business partner to his father’s

property and told her that he had hired workers to grow marijuana and that his

landscaping business was a cover3 ; (2) purchased the truck used by the workers on

the property using a false name; (3) occasionally visited his father’s property,

where the marijuana plants were in plain view; and (4) fled the day of his initial

appearance to avoid going to prison and admitted to Arizona police when he later

was pulled over for a traffic violation that they “had caught a big fish.” See United

States v. Wright, 392 F.3d 1269, 1277-78 (11th Cir. 2004) (explaining that “a

defendant’s flight, escape, resistance to arrest, concealment, assumption of a false

name, and related conduct [is] admissible evidence of consciousness of guilt, and

thus of guilt itself”). Based on this record, the evidence was not so tenuous that

Cox’s conviction was shocking.4


       3
        While Cox argues that his partner’s testimony was not credible, credibility
determinations are within the exclusive province of the jury and may not be revisited unless the
testimony is “incredible as a matter of law.” United States v. Calderon, 127 F.3d 1314, 1325
(11th Cir. 1997).
       4
         Cox also argues that the evidence failed to support the jury’s special finding that the
conspiracy involved over 1000 marijuana plants because evidence did not connect him to three
grow sites located off of his father’s property. But USFS agents testified that the three additional
grow sites (which contained 594 plants) contained similar marijuana plants in black trays and
starter cups and empty bags of potting soil as found at the initial site and on the Cox
property, which contained 724 plants.

                                                10
AFFIRMED.




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