United States Court of Appeals
                            FOR THE EIGHTH CIRCUIT
      ___________

      No. 08-1559
      ___________

United States of America,               *
                                        *
            Appellee,                   *
                                        *
      v.                                *
                                        *
Robert John Farrell,                    *
                                        *
            Appellant.                  *

      ___________
                                            Appeals from the United States
      No. 08-1561                           District Court for the
      ___________                           District of South Dakota.

United States of America,              *
                                       *
            Appellee,                  *
                                       *
      v.                               *
                                       *
Angelita Magat Farrell,                *
                                       *
            Appellant.                 *

                                 ____________

                             Submitted: November 11, 2008
                                Filed: April 17, 2009
                                 ___________

Before MELLOY, BOWMAN, and SMITH, Circuit Judges.
                                     ___________

MELLOY, Circuit Judge.

        A jury convicted Robert John Farrell and Angelita Magat Farrell of four counts
of peonage in violation of 18 U.S.C. § 1581, one count of conspiracy to commit
peonage in violation of 18 U.S.C. § 371, two counts of making false statements in
violation of 18 U.S.C. § 1001, one count of visa fraud in violation of 18 U.S.C. §
1546, and one count of document servitude in violation of 18 U.S.C. § 1592. The
Farrells appeal, arguing that the evidence was insufficient to support the jury’s verdict
as to the charges of peonage, conspiracy to commit peonage, and document servitude.
The Farrells further argue that the district court1 erred in admitting certain expert
testimony. Having jurisdiction under 28 U.S.C. § 1291, we affirm the convictions.

                                           I.

       The Farrells own and operate the Comfort Inn & Suites in Oacoma, South
Dakota. In both 2005 and 2006, the Farrells contracted to bring nine non-immigrant
workers from the Philippines to the United States under temporary visas for the stated
purpose of working as housekeepers in their hotel. The Government charged the
Farrells with committing crimes against four of the nine. The Farrells assert that the
Government presented insufficient evidence at trial to allow a reasonable jury to
convict them of peonage, conspiracy to commit peonage, and document servitude.

       “This court reviews the sufficiency of the evidence supporting a conviction de
novo, viewing evidence in the light most favorable to the government, resolving
conflicts in the government’s favor, and accepting all reasonable inferences that
support the verdict.” United States v. Phythian, 

, 811 (8th Cir. 2008)



      1
        The Honorable Charles B. Kornmann, United States District Judge for the
District of South Dakota.

                                          -2-
(quotation omitted). This court will “reverse only if no reasonable jury could have
found the defendant guilty beyond a reasonable doubt.” 

Thus,
we recount the facts in the light most favorable to the verdict.

      A. First Application for Non-Immigrant Workers—2005

       While visiting family in the Phillippines in 2005, the Farrells began actively
recruiting Filipino workers to come and work for them in the United States. After
soliciting several individuals, the Farrells submitted an I-129 Petition for a
Nonimmigrant Worker (“Petition”) to the Department of Homeland Security on
August 17, 2005. The Petition stated that they were seeking housekeepers from
October 1, 2005, until January 31, 2006, at a salary of $300 per week. The Farrells
were required to pay the government a one-time processing fee of $1200 with the
submission of the Petition.

       In addition to the Petition, the Farrells drafted employment contracts for each
of the nine workers they had solicited. As with the Petition, these contracts stated that
the Farrells would employ the workers as housekeepers and that the workers would
work six days per week for eight hours each day. The contracts set compensation at
$6.05 per hour and also provided for holiday and overtime pay. In addition to these
provisions, the contracts stated that the Farrells were responsible for housing the
workers and that each worker would reimburse the Farrells $150 per month for this
expense. The contracts also provided that the Farrells were responsible for the cost
of transportation to and from the United States, as required by law. After the Farrells
submitted the Petition and drafted the employment contracts, the workers filed their
applications for non-immigrant visas with the U.S. Embassy in Manila, Phillippines.
The applications reflected the terms of the employment contracts as recounted above,
including the promise that the Farrells would pay for the workers’ transportation to
and from the United States.




                                          -3-
       Prior to the consular officers’ adjudication of the workers’ visa applications, the
workers met with the Farrells in a Manila hotel. During this meeting, the Farrells
prepped the workers for the visa interviews at the Embassy. The Farrells also revealed
additional details about the job, including the fact that despite the provisions in the
employment contracts and the requirements of U.S. law, the Farrells would not
reimburse the workers for transportation to and from the United States. The Farrells
stressed, however, that the workers’ visas would be denied if the workers told this
information to the consular officers and that they should refrain from mentioning it.
The Farrells further stated that despite the contractual provisions, the workers would
not receive holiday or overtime pay. Finally, the Farrells informed the workers that
the $1200 Petition-processing fee would be divided equally among them.

       Thus, upon leaving for the United States, the workers were under the
impression that they would be making $6.05 per hour and working eight-hour days
for six days each week. They also knew that they would be responsible for
reimbursing the Farrells for the cost of transportation to and from the country, as well
as one-ninth of the processing fee. Despite beginning the employment relationship
financially indebted to the Farrells, the workers anticipated being able to pay back the
money soon after their employment began. Many looked forward to working in the
United States because the Philippines is a “poor country” with a “high unemployment
rate” and “great corruption,” and they anticipated that even with the debt payments,
they would be able to send money home to their families. The U.S. Embassy
approved the visas.

       When the workers arrived in South Dakota in November 2005, the employment
situation was not as they had anticipated. Angelita immediately required the workers
to surrender their passports, visas, and immigration documents. Many of the workers
were reluctant to do so but obeyed out of the “honor and respect” Filipino culture
demanded they show their employers. Upon starting their jobs, the Farrells informed
the workers that instead of an hourly wage they would be paid $3 per room. Because


                                           -4-
it took around one hour to clean a room to the Farrells’ standards, the workers were
making approximately one-half the wage the Farrells had promised (and had included
in the paperwork), which was well under minimum wage. If the rooms were not up
to the Farrells’ standards, Robert told the workers they would not be paid at all. The
Farrells further informed the workers that each of the nine would be individually
responsible for the entire amount of the $1200 processing fee, despite the fact that the
Farrells only paid the fee once.

       In addition to the processing fee, the Farrells began charging the workers for
transportation to and from work (which had not been agreed to in the employment
contract) and began charging them for personal items that the workers neither
requested nor desired. Thus, once in the United States, the workers’ debt increased
dramatically while the income with which they anticipated being able to pay down
that debt had decreased by at least one-half. Recognizing that the workers would not
be able to pay their increasing debt from their hotel paychecks, the Farrells required
that the workers obtain outside employment. The Farrells facilitated the workers’
interviews at local fast-food restaurants and other service-industry establishments.
Many of the locations where the workers interviewed eventually employed the
workers, in direct violation of their visas.

       Other than when at their non-hotel employment, the workers spent little time
away from the hotel. This was, in part, because of the manner in which the Farrells
controlled the workers’ free time. The workers were not permitted to leave their
shared apartment, even to visit the drug store, without asking permission from either
the Farrells or the hotel manager, Alma Navarro. Frequently, the Farrells told the
workers that they were not to speak with anyone outside of the hotel and that they
were prohibited from socializing with Americans. The prohibition against speaking
to other people went so far as to preclude the workers from speaking to the non-
Filipino workers who were employed at the same hotel.



                                          -5-
       When American co-workers at one of the fast-food restaurants invited several
of the workers to go bowling, Robert insisted on driving the workers to the alley and
remained there to supervise them. This was despite the fact that a co-worker had
volunteered to drive the workers home when they were finished. At one point,
without asking permission, several of the workers accepted an invitation from the fast-
food-restaurant shift manager to visit a local bar. The workers did not miss their
scheduled shifts at the hotel, and there was no evidence that the activity otherwise
interfered with the workers’ employment there. When the workers returned from the
outing, however, the Farrells summoned them into the hotel office and proceeded to
reprimand them for disobeying the rules against socialization. The workers testified
that they were afraid of Robert. The Farrells even told the workers that they were not
to accept rides from their co-workers, meaning that many were required to walk home
from work in the freezing cold and snow.

        In addition to the explicit prohibitions the Farrells placed on the workers, the
workers’ use of their free time was also constricted by the fact that they had very little
of it. Far from the eight-hour days the workers had anticipated, they regularly worked
upwards of thirteen hours per day, seven days a week, frequently traveling directly
from the hotel to their outside employment or vice versa. The workers’ living
situation was also not as anticipated. The Farrells did provide housing, but seven
workers were required to share one two-bedroom apartment. The Farrells paid only
$375 per month for the lease but still charged the workers $150 per person per month.
The workers were not given a key to the apartment; rather, Angelita and Navarro
retained possession of the key. The workers were thus forced to leave the door to the
apartment unlocked at all times. Frequently, Angelita would arrive at the residence
unannounced, enter the premises, and search through the workers’ belongings. In
another invasion of the workers’ privacy, Navarro would watch while the workers
opened their personal mail, all of which was sent to the hotel. The Farrells had told
the workers that the apartment was not registered with the post office and that their
mail would be lost if sent directly there.


                                           -6-
       Despite the volume of work, the workers’ income was still insufficient to meet
their mounting debt obligations. Motivated by the workers’ inability to pay their
debts, the Farrells instituted a debt-prioritization scheme. As part of this plan, the
Farrells required each of the workers to provide a breakdown of all of the paychecks
that they had received while in the country, including those from their outside
employment. In this accounting, the workers were also required to indicate how much
they had sent back to the Philippines and the purpose for which the money had been
sent. The Farrells also required a breakdown of each of the worker’s expenses in
South Dakota, including food, personal items, and telephone calls. The Farrells told
the workers that this accounting would allow the Farrells to determine how much
money they would allow each worker to spend and send home. One worker testified
that these requirements meant that she gave the Farrells over ninety percent of her
weekly income. When another worker pleaded to be allowed to keep more money so
she could pay for her sister’s tuition in the Philippines, the Farrells refused.

       To ensure that the workers adhered to their debt-prioritization scheme, the
Farrells forced the workers to sign contracts guaranteeing repayment and kept detailed
records of each worker’s debt. The Farrells would regularly hold meetings with the
workers during which they consulted their debt logs and severely berated the workers
for missteps at the hotel or spending money without permission. Robert always
emphasized the importance of debt repayment at these meetings, and to punctuate his
point, he frequently threatened to ship the workers back to the Philippines in a
“balikbayan box”2 if they attempted to run away or do anything behind the Farrells’
backs. The Farrells also stressed that the workers were in the United States by their
grace and that if the workers avoided their payment obligation the Farrells would call
immigration authorities. Following each group meeting, the Farrells held individual
meetings with the workers to discuss each person’s debt in detail. The workers

      2
        A balikbayan box is a small cardboard or wooden box that Filipinos living
abroad use to send gifts back to the Philippines. Given its purpose and size, it is
clearly not an appropriate method of travel for a living human being.

                                         -7-
testified that they were frequently scolded for spending too much money. Ultimately,
prior to the workers’ first departure from the United States, the Farrells required those
employed at the fast-food restaurant to endorse their last paychecks to the Farrells.

        Despite paying the Farrells the majority of their earnings, as the workers’ visas
were set to expire, they were all in much greater debt than they had been upon arriving
in the country. Each worker initially had been promised two trips to work at the hotel,
but the Farrells made them write letters establishing why they deserved to return.
Begrudgingly, the workers wrote letters requesting re-employment. The workers
testified that they had no interest in working for the Farrells but that it would have
been impossible to repay the debt by working in the Philippines. Because the Farrells
had made each worker sign a debt contract and had threatened the workers with
physical harm if they defaulted, the workers testified that they believed they had no
other option but to return to the United States again and fulfill their contractual duties
or face imprisonment or worse in the Philippines. The workers testified that they
would never have come to the United States in the first place had they known the
extent of debt for which they would be responsible.

      B. Second Application for Non-Immigrant Workers—2006

       The Farrells submitted their second I-129 Petition in early 2006. This time, the
Petition listed the workers’ salaries as $242 per week. Again, prior to the workers’
consular interviews, the Farrells met with the group. They explicitly told the workers
not to list their prior outside employment on the visa applications because the
applications would be denied. The Farrells also told the workers to tell the
government that the Farrells would pay for transportation to and from the United
States. The Farrells then proceeded, however, to require each worker to acknowledge
an additional $1200 debt for the transportation cost. At that meeting, the Farrells also
provided the workers with copies of fake checks as evidence that the Farrells had paid
the workers in accordance with the previous contract. The workers testified that they
had neither received nor previously seen these checks.

                                           -8-
       Upon the workers’ second arrival in the United States, the Farrells again
required the workers to turn over their passports and immigration documents. As
before, the workers did so in deference to their employers. The workers faced the
same cramped living situation, and some of them were without a bed on which to
sleep. Again, the Farrells prohibited the workers from socializing and required that
they even ask permission before making phone calls.

       The Farrells required the workers to sign a second debt contract, and in addition
to recording the workers’ income and mounting debt, the Farrells instituted a rigid
schedule of mandatory bi-weekly payments. To cover these payments, the Farrells
required that each worker surrender his or her hotel paycheck to them and post-date
additional checks in the amount of the bi-weekly payment obligation. The payment
amounts depended on the individual’s indebtedness, but they ranged from $361 to
$431 every two weeks. With a salary of only $242 per week, of which the workers
were required to pay $150 toward housing per month, plus additional amounts for
non-requested expenditures and personal items, the bi-weekly payments constituted
an amount greater than the workers’ salaries.

       As the workers’ debts mounted and their ability to pay diminished, the Farrells’
debt-focused meetings became increasingly hostile. The Farrells would spontaneously
call the meetings late at night and require those who were not working at the hotel to
come from home to attend, even if that meant rousing them from sleep. The workers
were not compensated for their attendance at the meetings. As before, the Farrells
would berate the workers for anything they had done wrong at the hotel and
emphasize the necessity of repayment. Robert frequently warned the workers not to
go “TNT” or “tago ng tago,” a Tagalog saying commonly used to refer to
undocumented immigrants in hiding. He told the workers that if they went TNT he
would find them and ship them back to the Philippines in a balikbayan box. Severely
frightened, the workers believed the Farrells would find them no matter where they
were. Robert repeated this threat several times per month both outside of and during
meetings. At least once, the threat appears in the minutes of a meeting.

                                          -9-
       The Farrells’ tirades against the workers would often last into the early hours
of the morning. On at least one occasion, after one worker refused to provide post-
dated checks in the amount of the bi-weekly payment, the Farrells kept her in the
meeting room until six in the morning. During that time, Robert continually yelled
at her despite the fact that the worker was extremely frightened and crying. Because
she was scheduled to work the next morning’s shift at the hotel, once the Farrells
released her she began her shift without having slept. Two other workers testified that
when they sent money back to their families without asking permission, they were
called into the office and reprimanded, being told that the Farrells were the only ones
who would decide how the workers spent their money. One of the workers testified
that Robert was so angry during this meeting that he feared Robert would punch him.
The worker further testified that he was unable to do anything to stop the abuse
because he was paralyzed by fear and did not “know anything about [how it works]
here in America.” He was convinced that Robert had the power to do to the workers
whatever he wanted to do.

        During this entire time, only one worker was able to leave the United States.
After lying about how her mother was in the hospital and dying, the Farrells allowed
her to return to Manila, but they controlled her every movement up until her departure.
Angelita escorted the worker to the airport and only returned her passport when it was
required to pass through security and board the plane. The woman never returned to
the United States to work for the Farrells, but she testified that they harassed her via
e-mail and telephone to ensure that she paid her debt. Eventually, as a result of the
harassing conduct, the worker contacted the U.S. Embassy in Manila and an
investigation was started.

       In June 2006, two other workers attempted to leave after the Farrells accused
them of stealing tips from the hotel rooms and humiliated them in front of the other
workers as punishment. Their desire to return to the Philippines caused immediate
conflict. Following a verbal altercation at the hotel, the Farrells accompanied the

                                         -10-
workers to their apartment, rushing them to get their belongings together so that the
Farrells could take them to the airport. The Farrells informed the workers that
immigration authorities were waiting to deport them, and when the workers attempted
to call someone and ask for help, Angelita confiscated the telephone. Eventually,
Robert called the chief of police and the FBI seeking to have the workers arrested. The
chief of police arrived and talked to the workers, informing them that they could stay
until their scheduled return flight, which was less than one week later. The police
chief acknowledged that the workers were “terrified” of the Farrells and refused to
speak in front of them. When the police chief left, the Farrells stayed outside of the
apartment to prevent the workers from leaving. When the workers expressed concern
about being able to purchase food, the Farrells said they would have to make do with
what was in the refrigerator.

        Still without their passports and thus unable to leave on their own, but fearful
of what would happen, the workers found an old phone from the hotel, plugged it in,
and called the manager of the fast-food restaurant (where some of the workers were
employed) to ask for help. The workers also called the county attorney. Sometime
thereafter, the chief of police returned to the apartment because, upon reflection, he
felt as though the Farrells had used him to intimidate the workers. Sensing something
was wrong, both he and the county attorney arranged for the workers to be removed
from the apartment and the Farrells’ control. The county attorney testified that it was
“very apparent” that the workers were living in fear of the Farrells.




                                         -11-
                                           II.

      A. Peonage

       Peonage is “compulsory service in payment of a debt.” Bailey v. Alabama, 

, 242 (1911). “[C]ompulsory service” is the equivalent of “involuntary
servitude,” 

which the Supreme Court has defined as “a condition of
servitude in which the victim is forced to work for the defendant by the use or threat
of physical restraint or physical injury, or by the use or threat of coercion through law
or the legal process.” United States v. Kozminski, 

, 952 (1988).3 Thus,
in order to prove peonage, the government must show that the defendant intentionally
held a person against his or her will and coerced that person to work in order to satisfy
a debt by (1) physical restraint or force, (2) legal coercion, or (3) threats of legal
coercion or physical force. See 

In determining whether “physical or
legal coercion or threats thereof could plausibly have compelled the victim to serve,”
the jury is entitled to consider “evidence of other means of coercion, or of poor
working conditions, or of the victim’s special vulnerabilities.” 

case, a reasonable jury could have found that the Government proved the
elements of peonage beyond a reasonable doubt. As discussed above, the workers
testified extensively about their treatment while in the Farrells’ employment. They
testified that Robert threatened them with physical force; namely, that if they
attempted to “run away” he would find them, “put them in a balikbayan box,” and ship
them back to the Philippines. Despite the Farrells’ argument to the contrary, it is
indisputable that this statement was a threat of physical force. The evidence thus


      3
        Jury Instruction 16 defined “involuntary servitude” as follows: “[A] condition
of compulsory service in which the alleged victim is compelled to perform labor or
services against the alleged victim’s will for the benefit of another person due to the
use or threat of physical restraint or physical injury, or by the use or threat of arrest,
prosecution, or imprisonment. . . . The use or threat of a civil lawsuit does not make
the labor involuntary.”

                                          -12-
supports a finding that the workers were reasonable in inferring from these statements
that the Farrells were willing to harm them if they attempted to stop working and
leave.

       The workers also testified about the Farrells’ threats to have immigration
authorities arrest and deport the workers if they did not “comply” with the Farrells’
directives. The Farrells also threatened to call immigration authorities (and did
ultimately call the FBI and the chief of police) after two workers expressed a desire
to leave. These threats of arrest and deportation came despite the fact that the workers
gave no indication that they would resist returning to the Philippines. The Farrells
argue that they were legally entitled to explain to the workers that their visas were
contingent on continued employment at the hotel. It is another thing entirely,
however, to threaten to have immigration authorities arrest the workers as a
consequence of failing to abide by the Farrells’ rules—rules that included a
prohibition on speaking with people outside of the hotel, presumably for fear that the
workers would reveal the conditions of their employment—or as a tactic to keep the
workers until the end of their contracts by exploiting their fears of being imprisoned
by immigration authorities if they left early. See United States v. Veerapol, 

, 1131, 1132 (9th Cir. 2002) (finding sufficient evidence to sustain a conviction
for involuntary servitude, based, in part, on the employer’s statement that “the police
in the United States would arrest [the victim] as an illegal alien were [the victim] to
seek their help”).

       In addition to showing the Farrells threatened the workers with physical force,
arrest, and imprisonment, the evidence further supports the jury’s finding that these
threats actually compelled the workers to serve in order to satisfy their debt when
viewed in conjunction with the workers’ working and living conditions, as well as
their particular vulnerabilities. See 

. The evidence is
clear that the workers subjectively feared the Farrells. They believed Robert when he
threatened to hunt them down and ship them back to the Philippines in a balikbayan


                                         -13-
box, and they feared for their lives and the lives of their children if they were not able
to meet their debt obligations or left the Farrells’ employment. Their fear of Robert
was not unfounded as the evidence shows he regularly lost his temper during meetings
at the hotel, revealing to the workers his volatile temper and sparking fears that he
would resort to physical violence. There was also sufficient evidence to show that the
workers reasonably believed that their employers were “powerful people” and could
indeed “hunt them down” if the workers left. For example, after the Farrells had some
initial trouble obtaining visas in Manila, Robert showed the workers a letter from
congresspersons in South Dakota and told them that the letter would fix the problem.
The visas were subsequently approved, leading the workers to believe that the Farrells
were well connected politically.

       The workers’ employment and living conditions also provide support for the
jury’s conclusion that the Farrells’ threats “plausibly . . . compelled the victim[s] to
serve.” 

In short, the conditions were difficult. The workers labored
lengthy back-to-back shifts at the hotel and their outside jobs—employment facilitated
and required by the Farrells—to meet their mandatory bi-weekly debt payments. One
worker testified that this rigorous schedule precluded sleep at least four times per
week. See 

–31 (discussing circumstances such as
“excessive working hours” that supported a jury finding of involuntary servitude).
The Farrells also denied the workers time off when the workers so requested. See
United States v. Sabhnani, 

, 620 (E.D.N.Y. 2008) (recounting
numerous “abuses” that served as a basis for a conviction, including twenty-hour work
days and no regular days off). In addition to the long hours, the workers were not paid
in accordance with their contract and were at times paid below minimum wage.

       The Farrells continually isolated the workers from others in the community by
refusing to allow them to speak or socialize with non-Filipino co-workers, by
channeling all mail through the hotel where it had to be opened in the presence of the
hotel manager, by refusing to allow them to leave the apartment to perform even the


                                          -14-
most mundane tasks without asking for permission, and by refusing to allow the
workers to travel or otherwise spend their free time outside the hotel or apartment.
See, e.g., 

–31 (“Veerapol isolated her workers . . . by
prohibiting them from . . . going to stores, speaking with her houseguests and the
customers at the restaurant . . . or using the telephone or mail.”); United States v.
Djoumessi, 

, 549 (6th Cir. 2008), cert. denied, 

(2009);

. In addition to this social isolation, the Farrells
attempted to control every other aspect of the workers’ lives. They dictated the
amount of money the workers were able to send back to the Philippines and for what
purpose; required the workers to post-date checks that the workers knew they would
not be able to cover unless they continued working at the hotel; and kept a key to the
workers’ residence so that they could conduct random inspections of the premises
while refusing to allow the workers a key of their own.

       Furthermore, the coercive nature of the threats is amplified by the workers’
“special vulnerabilities,” 

, which include the fact that the
workers were in the United States under temporary-work visas sponsored by the
Farrells.4 Many of the workers arrived in the United States with very little money and
were entirely dependent upon the Farrells for their housing and transportation. The
fact that the Farrells required the workers to have outside jobs also added to their
vulnerability. Even if the workers believed that they could leave the Farrells’
employment and seek help, the Farrells made them acutely aware that they could have
them deported for holding jobs outside of the scope of their visas. This fear was not


      4
        While debt is an element of the peonage charge, we also cannot ignore the
creditor–debtor relationship as a source of vulnerability. Far from simply owing the
Farrells money, the workers relationship with their employers was more akin to one
of debt bondage rather than simple debt. Given the continually mounting expenses,
at no point was the value of the workers’ labor sufficient to liquidate the debt and
there was, in effect, no limit to the length of the services required to satisfy the
obligation or even a limit on the amount owed.

                                        -15-
unfounded. At some point during July 2006, even after she was under investigation,
Angelita sent a letter to Immigration and Customs Enforcement officials at the
Minneapolis airport to inform the agency that several of the workers (who law-
enforcement officials had already removed from the Farrells’ control) had taken
unauthorized employment at various locations while they were working for the
Farrells.

       The Farrells argue that the possibility of deportation alone was insufficient to
provide the requisite compulsion for peonage because being deported to the
Philippines was not the equivalent of “imprisonment or worse,” and they cite a First
Circuit case for that proposition. See United States v. Alzanki, 

, 1004 (1st
Cir. 1995) (“[T]he evidence must establish that the victim reasonably believed she was
left with no alternative to continued servitude that was not the equivalent of
imprisonment or worse.” (citation omitted)). In other words, the Farrells contend that
the workers could have simply stopped working and been deported.

       Even assuming, as the Farrells’ argument requires, that the only thing that kept
the workers laboring was a fear of being deported, we are not persuaded. Here, the
threat of deportation was more than a threat of removal from the United States or a
threat to legitimately use the legal process to ensure that the workers abided by the
terms of their visas. The Farrells had made it clear during various meetings that they
would seek to collect the money the workers owed no matter where the workers went.
It would have been extremely difficult, if not impossible, for the workers to meet their
debt obligations on salaries in the Philippines. Based on Robert’s threats that he
would hunt the workers down and harm them if they failed to pay their debts, it was
not unreasonable for the workers to believe that failure to pay their debt, even when
back in the Philippines, would result in physical harm. As a consequence, here the
threat of deportation was, in essence, a threat of force. See 

(“[I]t is possible that threatening . . . an immigrant with deportation could
constitute the threat of legal coercion that induces voluntary servitude . . . .”); see also


                                           -16-


; 

–05 (finding that the victim’s
awareness of the “severely restrictive conditions” that she would encounter in the
country to which she would be deported enabled the jury to conclude that “threatened
with deportation . . . [the victim] confronted an alternative to continued involuntary
service which she reasonably considered at least as severe as imprisonment”).

       The Farrells repeatedly claim that the workers’ employment was voluntary and
because voluntariness is a defense to the peonage charge, it is impossible for the
workers’ employment to have constituted involuntary servitude. As evidence of the
voluntary nature of the employment, they cite the workers’ return to the United States
in the spring of 2006 for a second contractual term and to the fact that they allowed
one worker to return to the Philippines to care for her ailing mother. Despite their
argument, however, based on the evidence recounted above, a reasonable trier of fact
could have concluded that the workers were not, in fact, free to leave and that it was
the Farrells’ coercive acts that compelled the workers to stay in the United States and
return on a second work visa in order to satisfy their debts.

       The fact that the workers left the country and then returned does not
automatically make their employment voluntary. As discussed above, the workers
would not have been able to pay their debt by working in the Philippines, and they
believed that the Farrells would physically harm them if they failed to pay. Thus, a
reasonable jury could conclude that the workers believed they had no choice but to
return to United States and did not do so voluntarily. See United States v. Bibbs, 

, 1168 (5th Cir. 1977) (“[A] defendant is guilty of holding a person to
involuntary servitude if the defendant has placed him in such fear of physical harm
that the victim is afraid to leave, regardless of the victim’s opportunities for escape.”).
Even assuming that there were points at which the workers could have escaped the
Farrells’ control, a rational jury could have concluded that the workers’ employment
“was involuntary for at least some portion of [their] stay. And that involuntary portion
would suffice to sustain the conviction.” 

–53 (emphasis


                                           -17-
in original) (citing 18 U.S.C. § 1584, which requires the involuntary servitude be for
“any term”). Furthermore, once in the United States, it is undisputed that the workers
needed their passports and immigration documentation to leave the country. It is also
undisputed that these documents remained in the possession of the Farrells during the
workers’ entire stay. Realistically, without these documents, the workers were
required to remain in the command, if not the employment, of the Farrells.

       Given the above, a reasonable jury could have found that the Government
presented sufficient evidence to prove beyond a reasonable doubt that the Farrells’
threats of physical force and arrest compelled the workers to serve in order satisfy
their debts. The evidence establishes that the workers reasonably believed that they
had no option but to continue working for the Farrells. Accordingly, the conviction
for peonage is affirmed.

      B. Conspiracy to Commit Peonage

       The jury concluded that the Farrells engaged in conspiracy to commit peonage
in violation of 18 U.S.C. § 371. The Farrells again contest the sufficiency of the
evidence stating that they did not hold the workers in a condition of peonage and had
no agreement to do so. To prove conspiracy under § 371, the Government must show
beyond a reasonable doubt that the Farrells knowingly “entered into an agreement or
reached an understanding to commit a crime,” and that at least one of the Farrells
“overtly acted in furtherance of the agreement.” United States v. Bertling, 

, 808 (8th Cir. 2007) (quotations omitted). “An agreement forming a conspiracy
may be either explicit or implicit.” United States v. Boesen, 

, 853 (8th
Cir. 2008).

       The jury’s conviction of the Farrells of conspiracy to commit peonage was
sufficiently supported by the Government’s evidence. The jury could infer from the
Farrells’ joint and extensive involvement in the visa application procedure, in the
running of the hotel, and in the administration of the housing that the Farrells

                                        -18-
knowingly entered into an agreement to hold the workers in a condition of peonage.
See United States v. Tipton, 

, 595–96 (discussing the evidence of joint
involvement of the co-conspirators). Additionally, any of the acts described in detail
above are sufficient to satisfy the overt-action element once the jury determined that
there was an agreement. See 

affirm the conviction for conspiracy to
commit peonage.

      C. Document Servitude

       The Farrells also contest the sufficiency of the evidence with regard to their
conviction for document servitude. In order to prove that the Farrells committed
document servitude, the Government must show that the Farrells (1) concealed,
removed, confiscated, or possessed the workers’ passports, visas, or other immigration
documents; (2) did these acts in the course of violating the peonage statute with the
intent to violate the statute; and (3) acted knowingly and intentionally. 18 U.S.C. §
1592(a).

      The evidence at trial was sufficient for a reasonable jury to convict the Farrells
of document servitude. The Farrells do not contest that Angelita confiscated the
workers’ passports, visas, and entry cards upon their arrival in the United States in
both 2005 and 2006. The Farrells also do not contest that they knowingly retained
possession of these documents throughout the workers’ entire stay. Numerous
workers testified that they did not possess their passports while working at the hotel
and that the Farrells took the documents to “control” them. Angelita only returned
one worker’s passport when that worker was at the airport and ready to board the
plane. The chief of police further indicated that even after he specifically requested
that Robert turn the workers’ immigration documents over to the workers, Robert still
refused. It was only after the chief of police threatened to arrest him for theft that
Robert complied.




                                         -19-
       In addition to having confiscated and knowingly possessed the passports, as
outlined extensively above, there was sufficient evidence that the Farrells had the
intent to commit peonage and retained the documents while committing peonage.
Because the evidence was such that a reasonable jury could have concluded that the
Farrells committed document servitude, we affirm the conviction.

                                           III.

       The Farrells also challenge the district court’s admission of expert testimony
by government witness Joy Zarembka. They allege that her testimony invaded the
province of the jury to weigh the evidence, make credibility determinations, and fact-
find. When a defendant “fails to object to the admission of evidence at trial, we
review for plain error.” United States v. Eagle, 

, 801 (8th Cir. 2008). The
defendant has the burden to prove that there was an error, that it was plain, and that
the error affected substantial rights. 

three conditions are met, we may then
exercise our discretion to notice a forfeited error, but only if the error seriously affects
the fairness, integrity, or public reputation of judicial proceedings.” 

testimony may be used to “assist the trier of fact to understand the
evidence or to determine a fact in issue,” Fed. R. Evid. 702, an expert witness may not
usurp the jury’s function to weigh evidence and make credibility determinations.
United States v. Azure, 

, 339–40 (8th Cir. 1986). The Government
called Zarembka, an expert in human trafficking and domestic-worker exploitation,
as its first witness. Zarembka testified about various warning signs in
employer–employee relationships that often indicate the employee is not laboring
voluntarily but rather in a “climate of fear” or psychological coercion. She further
testified that she believed several of these warning signs were present in the Farrells’
relationships with the workers and that the workers did, in fact, labor in a “climate of
fear.”




                                           -20-
        Zarembka’s testimony was relevant insofar as it provided this broader context
for the jury to understand the workers’ actions, to understand the conditions in which
they may have labored, and to assess the truthfulness of their allegations. Cf. United
States v. Kirkie, 

, 766 (8th Cir. 2001) (allowing testimony “regarding
characteristics of sexually abused children in general and as they compared with the
characteristics exhibited by the victim in this case”). The expert testimony went
further than this, however, and it usurped the jury’s function when Zarembka opined
on the strength of the Government’s case and the credibility of its witnesses through
references to the “incredible” and “strong” nature of the evidence against the Farrells.
The testimony also invaded the fact-finding function of the jury when Zarembka
testified that the workers “were not controlling their money” and that they were
“forced to pay [the debt].” One of the issues before the jury with regard to the
peonage charge was whether or not the workers stayed voluntarily. Given this
required finding, the expert’s testimony was not simply a factual conclusion but rather
an attempt to express an opinion as to the guilt of the Farrells and a manner of stating
that the forthcoming worker witnesses were telling the truth. See United States v.
Whitted, 

, 787 (8th Cir. 1993) (finding that a doctor’s “diagnosis of sexual
abuse was only a thinly veiled way of stating that [the witness] was telling the truth”).

       Thus, we agree with the Farrells that portions of the expert testimony invaded
the province of the jury. We do not believe, however, that the error affected their
substantial rights. Other than the expert-witness testimony, there was ample evidence
upon which a jury could have found that the Farrells committed the substantive
offenses charged. Furthermore, to the extent that the jury relied on the “climate of
fear” theory, testimony from the victims, the police chief, the county prosecutor, and
other witnesses readily established the existence of the factors that Zarembka
discussed. See United States v. Montanye, 

, 193 (8th Cir. 1993) (en
banc) (requiring that the error prejudicially affect the district court proceedings). As




                                          -21-
a result, the district court’s error in not excluding portions of the expert testimony is
an insufficient basis upon which to overturn the jury’s verdict.

                                          IV.

      For the foregoing reasons, we affirm the convictions.
                      ______________________________




                                          -22-