                       RECOMMENDED FOR FULL-TEXT PUBLICATION
                           Pursuant to Sixth Circuit I.O.P. 32.1(b)
                                   File Name: 13a0330p.06

               UNITED STATES COURT OF APPEALS
                                FOR THE SIXTH CIRCUIT
                                  _________________


                                                X
                           Plaintiff-Appellee, -
 UNITED STATES OF AMERICA,
                                                 -
                                                 -
                                                 -
                                                     No. 12-3212
          v.
                                                 ,
                                                  >
                                                 -
                        Defendant-Appellant. -
 PAUL H. VOLKMAN,
                                                N
                  Appeal from the United States District Court
                 for the Southern District of Ohio at Cincinnati.
             No. 1:07-cr-60-3—Sandra S. Beckwith, District Judge.
                                  Argued: June 13, 2013
                        Decided and Filed: November 21, 2013
  Before: McKEAGUE and DONALD, Circuit Judges; LAWSON, District Judge.*

                                   _________________

                                        COUNSEL
ARGUED: Edwin A. Perry, FEDERAL PUBLIC DEFENDER’S OFFICE, Memphis,
Tennessee, for Appellant. Christopher K. Barnes, UNITED STATES ATTORNEY’S
OFFICE, Cincinnati, Ohio, for Appellee. ON BRIEF: Stephen B. Shankman,
FEDERAL PUBLIC DEFENDER’S OFFICE, Memphis, Tennessee, for Appellant.
Christopher K. Barnes, UNITED STATES ATTORNEY’S OFFICE, Cincinnati, Ohio,
for Appellee.
                                   _________________

                                         OPINION
                                   _________________

        BERNICE BOUIE DONALD, Circuit Judge. When a doctor first enters the
practice of medicine, he or she swears to abide by a prime directive of the profession:
“First, do no harm.” Paul Volkman breached this sacrosanct tenet when he prescribed

        *
        The Honorable David M. Lawson, United States District Judge for the Eastern District of
Michigan, sitting by designation.


                                              1
No. 12-3212           United States v. Volkman                                                 Page 2


narcotics to addicts and individuals with physical, mental, and psychological frailties.
A federal jury looked at Volkman’s actions and found him guilty of breaking several
laws, chief among them the law prohibiting the unlawful distribution of controlled
substances. After receiving the jury’s verdict, the district court sentenced Volkman to
four consecutive terms of life imprisonment, to be served concurrently with a number
of less-lengthy terms.

        Volkman now appeals, contending that several errors arose throughout the course
of his trial and sentencing. We disagree, and we AFFIRM Volkman’s convictions and
sentence.

                                                  I.

        Paul Volkman is a former doctor who cast himself as a “pain management
physician.” Educated at the University of Chicago, Volkman holds an M.D. and Ph.D.
in pharmacology from that institution. See Volkman v. United States Drug Enforcement
Admin., 567 F.3d 215, 217 (6th Cir. 2009). Before the events leading up to his
conviction, he was board-certified in emergency medicine and was a “diplomat” of the
American Academy of Pain Management.

        Despite his professional pedigree, Volkman fell into hard times in 2003. He had
been sued on several occasions, settling some cases and losing others. See Volkman,
567 F.3d at 217. By the time his legal woes were over, he had no malpractice insurance
and no job.

        As part of his effort to rectify the latter, Volkman called Denise Huffman at the
Tri-State Health Care clinic, asking about job opportunities. Eventually, Denise1 hired
him to provide the clinic’s medical services. They agreed that Volkman’s salary would
be $5,000 per week—eventually, the amount was upped to $5,500 per week.




        1
           To minimize confusion, we will refer to Denise Huffman and her daughter, Alice Huffman Ball,
by their given names.
No. 12-3212         United States v. Volkman                                       Page 3


         Tri-State operated as a cash-only clinic. Pain medication was its bread and
butter. At its peak, Tri-State and its staff saw an average of eighteen to twenty patients
a day.

         Volkman worked without incident during his first few months at the clinic. But
approximately six months into the job, his practice encountered a major hiccup—local
pharmacies refused to fill the clinic’s prescriptions, citing concerns of improper dosing.
Volkman’s solution? Open a dispensary in the clinic. Volkman asked Denise’s
daughter, Alice Huffman Ball, to research the process for obtaining a license to operate
a dispensary. Denise objected and raised concerns, but Volkman assured her that “he
was a doctor[,] so he could dispense his own medication and he could take care of
everything.”

         Volkman submitted to the Ohio Board of Pharmacy an application for a license
to distribute controlled substances. Board representatives conducted an inspection of the
clinic grounds, during the course of which they found a Glock in the safe where the
drugs were stored. Despite this discovery, the Board issued a license after its initial
inspection.

         Agents from the Board conducted a follow-up inspection in December 2003.
This time, they saw several problems with the new dispensary’s practices. For instance,
the dispensary logs were sloppily maintained; Volkman provided little oversight over
recordkeeping processes. No licensed physician or pharmacist oversaw the actual
dispensing process. Patients returned unmarked and intermixed medication.

         By February 2004, the clinic took adequate measures to ameliorate the Board’s
administrative concerns. But the clinic still had its problems. Volkman was in charge
of the dispensary, but did a poor job of regulating access—the drug safe’s security was
porous, with unauthorized personnel regularly accessing the pharmaceutical stockpile
contained inside. Despite these issues, the dispensary saw much activity—it purchased
135,900 dosage units of oxycodone between July and December 2003, 457,100 dosage
units for the entirety of 2004, and 414,200 dosage units between January and September
2005.
No. 12-3212        United States v. Volkman                                        Page 4


       It eventually became clear that Volkman’s medical practice followed a
questionable pattern.   Drug addicts, drug peddlers, or individuals otherwise not
complaining of pain would come to see him as his “patients.” Very little was done in
terms of taking medical histories or conducting physical examinations. Volkman would
regularly prescribe a drug cocktail consisting of opiates (such as oxycodone and
hydrocone) as well as sedatives (diazepam, alprazolam, and carisoprodol; more
commonly referred to as Valium, Xanax, and Soma). He had a tendency of first
resorting to narcotics, disregarding first lines of treatment for pain management such as
non-steroidal anti-inflammatory drugs (NSAIDs).

       A federal investigation of Tri-State led to a search of the clinic facility on June
7, 2005. Medical personnel accompanying the investigative team saw that the clinic was
in utter disarray. Urine specimen cups, filled with urine, were scattered all over the
floor. The clinic had no equipment to view X-rays and MRI results. Miscellaneous pills
were strewn all throughout the clinic premises.

       Three months after the investigation, Denise terminated Volkman’s employment
because she “could no longer get along with him” and because there was “no control.”
In her words, “Dr. Volkman did what Dr. Volkman wanted to do.” Volkman decided
to open his own shop in Ohio—first in Portsmouth, and later in Chillicothe.

       Twelve of Volkman’s patients died during his tenure at Tri-State and during the
early months of his new practice. Kristi Ross, Steve Hieneman, Bryan Brigner, and
Earnest Ratcliff were four of these patients.

       A grand jury returned an indictment against Volkman, Denise, and Alice,
charging them with one count of conspiring to unlawfully distribute a controlled
substance in violation of 21 U.S.C. § 841(a)(1) (the Controlled Substances Act or
“CSA”), two counts of maintaining a drug-involved premises in violation of 21 U.S.C.
§ 856(a)(1), eight counts of unlawful distribution of a controlled substance leading to
death in violation of 21 U.S.C. §§ 841(a)(1) and 841(b)(1)(C), and four counts of
possession of a firearm in furtherance of a drug-trafficking crime in violation of
18 U.S.C. §§ 924(c)(1) and (2). Volkman was charged separately with five additional
No. 12-3212         United States v. Volkman                                       Page 5


counts of unlawful distribution of a controlled substance leading to death, as well as two
additional counts of maintaining a drug-involved premises. His co-defendants, Denise
and Alice, entered into plea agreements with the Government and testified against their
former colleague.

       After a thirty-five-day trial, a jury convicted Volkman on the lone conspiracy
count, seven counts of unlawful distribution that did not lead to death, four counts of
unlawful distribution leading to death, four counts of maintaining a drug-involved
premises, and one count of possessing a firearm in furtherance of a drug-trafficking
offense. The jury acquitted him on one count of unlawful distribution, as well as one
count of possessing a firearm in furtherance of a drug-trafficking offense.

       The district court sentenced Volkman to four consecutive terms of life
imprisonment for the counts of unlawful distribution leading to death, to be served
concurrently with a sentence of 240 months for the counts of conspiracy and unlawful
distribution not leading to death, 120 months for the drug-related premises counts, and
60 months for the firearm count, followed by three years of supervised release. Volkman
timely appealed.

                                           II.

       Volkman divides his argument into four parts. He first argues that the district
court erred by denying a proposed jury instruction derived from the Supreme Court’s
decision in Gonzales v. Oregon, 546 U.S. 243 (2006). Next, he contends that the
Government’s expert witnesses improperly provided legal conclusions as to whether
Volkman’s actions had a “legitimate medical purpose.” Third, he claims that there was
insufficient evidence to support the jury’s guilty verdict on several charges. Finally, he
challenges the reasonableness of his sentence on numerous grounds.

       First, we turn to Volkman’s jury-instruction argument. We review a denial of a
proposed jury instruction for an abuse of discretion. United States v. Theunick, 651 F.3d
578, 589 (6th Cir. 2011). Under this standard of review, we may reverse a district
court’s denial only if the proposed instruction “is (1) a correct statement of the law,
No. 12-3212         United States v. Volkman                                         Page 6


(2) not substantially covered by the charge actually delivered to the jury, and (3)
concerns a point so important in the trial that the failure to give it substantially impairs
the defendant’s defense.” United States v. Franklin, 415 F.3d 537, 553 (6th Cir. 2005)
(citation and quotation marks omitted).

        Volkman sought to have the following language included in the jury charge: “In
other words, in order to find the defendant guilty, you must find that he used his
prescription-writing power as a means to engage in the illicit drug-dealing and
trafficking as conventionally understood.” As we previously noted above, this language
comes directly from the Supreme Court’s decision in Gonzales. See 546 U.S. at 269-70.
Accordingly, Volkman contends that the proposed language—copied verbatim from
Gonzales—reflected a correct statement of the law that should have been included in the
district court’s instructions to the jury.

        Verbatim, however, does not necessarily mean correct. Context is critical, and
in the present context of federal criminal law, Gonzales provides us with little guidance.

        We join our sister circuits in making this observation. In United States v. Lovern,
590 F.3d 1095 (10th Cir. 2009), the Tenth Circuit commented on Gonzales’
relevance—or lack thereof—in the setting of a criminal prosecution. The court
explained that Gonzales dealt only with the question of the Attorney General’s ability
to define “legitimate medical purpose” in light of state medical standards to the contrary.
See id. at 1100. Gonzales was decided in the setting of administrative law, not criminal
law. In the court’s view, Gonzales was not relevant to the criminal prosecution at issue
in Lovern because there was “no interpretive rule seeking to define a practice as lacking
any legitimate medical purpose, let alone a rule that conflict[ed] with a state’s
assessment of the legitimacy of that practice.” Id. Instead, the Lovern court noted that
the Government properly sought to prove the lack of a legitimate medical purpose by
evidentiary means, leaving the question of what constitutes “the usual course of
professional practice” for a jury to sort out. See id.

        The Eighth Circuit made similar observations in United States v. Kanner,
603 F.3d 530 (8th Cir. 2010), where it adopted and expanded upon the Tenth Circuit’s
No. 12-3212        United States v. Volkman                                         Page 7


reasoning. There, a defendant argued that the indictment should have included the same
language from Gonzales that Volkman relies upon now. Id. at 533. The Kanner court
rejected the defendant’s argument by quoting the Lovern decision. Id. at 533-34. It
added to the Lovern court’s conclusions by noting that “Gonzales did not supplant the
standard for violations of the CSA.” Id. at 535. “Rather, post-Gonzales, knowingly
distributing prescriptions outside the course of professional practice is a sufficient
condition to convict a defendant under the criminal statutes relating to controlled
substances.” Id. (quoting United States v. Armstrong, 550 F.3d 382, 397 (5th Cir. 2008),
cert. denied, 130 S. Ct. 54, 175 L. Ed. 2d 44 (2009)).

        As our sister circuits have suggested, Gonzales did not impose new requirements
to prove a violation of the CSA. Instead, the statement that Volkman now quotes was
merely part of the Court’s commentary about statutory intent, federalism, and
rulemaking authority—none of which is at issue here. See Gonzales, 546 U.S. at 270.

        In the past, we have endorsed a broad approach to determining what conduct falls
outside the accepted bounds of professional practice so as to constitute a CSA violation,
eschewing a preestablished list of prohibited acts in favor of a case-by-case approach.
See United States v. Kirk, 584 F.2d 773, 784 (6th Cir. 1978). Simply put, Volkman’s
proposed instruction would have needlessly narrowed the scope of the jury’s inquiry to
a question of whether Volkman engaged in “conventional” drug dealing and trafficking
by using his prescription power. By narrowing the scope of the jury’s deliberation in
such a manner, Volkman’s instruction would have been inconsistent with our
endorsement of the broad approach, improperly cabining a decision that is properly left
to the jury.

        Moreover, the district court raised fair questions about the nebulousness of the
proposed instruction. What does it mean for drug dealing and trafficking to be
“conventionally understood”? If Volkman’s goal was to conjure up the unsavory specter
of “street” drug dealing—complete with imagery of shady characters conducting quick,
suspicious handoffs—then his instruction was not an accurate statement of the law, for
“street” drug dealing is not necessary to prove a violation of the CSA. It is not difficult
No. 12-3212         United States v. Volkman                                       Page 8


to see, however, how a lay juror might think that proof of such “street dealing” was
necessary for conviction under Volkman’s proposed standard. In that respect, we agree
with the district court that the instruction would have “muddied the waters,” thereby
providing an inaccurate statement of the law.

       Gonzales did nothing to alter the reality that “‘knowingly distributing
prescriptions outside the course of professional practice is a sufficient condition to
convict a defendant under the criminal statutes relating to controlled substances.’”
Kanner, 603 F.3d at 535 (quoting Armstrong, 550 F.3d at 397). Volkman’s proposed
jury instruction improperly would have cabined the scope of what the jury could
consider, thereby providing an inaccurate statement of law. Therefore, the district court
correctly denied Volkman’s request.

       Our decision to uphold the district court’s denial is reinforced by the second
prong of our review: whether the jury charge issued by the district court substantially
covered what Volkman sought to convey by his proposed instruction. We conclude that
the jury charge was not only adequate, but an example of model instructions for cases
such as this one.

       After reviewing the elements of a § 841(a)(1) offense and the meaning of certain
terms such as “distribute,” “dispense,” and “practitioner,” the district court provided a
lay explanation of the contours of the crime. It stated:

              No one can avoid responsibility for a crime by deliberately
       ignoring the obvious. If you are convinced that the defendant
       deliberately ignored a high probability that the controlled substances as
       alleged in these counts were distributed or dispensed outside of the
       course of the professional practice and not for a legitimate medical
       purpose, then you may find that the defendant knew that this was the
       case.

(DE 482, PageID 8588-89.) Next, the court elaborated on the burden of proof:

              But you must be convinced beyond a reasonable doubt that the
       defendant was aware of a high probability that the controlled substances
       were distributed or dispensed outside the course of professional practice
       and not for a legitimate medical purpose, and that the defendant
No. 12-3212          United States v. Volkman                                       Page 9


       deliberately closed his eyes to what was obvious. Carelessness or
       negligence or foolishness on his part are not the same as knowledge and
       are not enough to find him guilty on any of these counts. This of course
       is all for you to decide.

(DE 482, PageID 8589.) After explaining the textbook definition of “usual course of
professional practice,” the trial court connected the definition to the instant case:

       A physician’s own individual treatment methods do not, by themselves,
       establish what constitutes a “usual course of professional practice.” In
       making medical judgments concerning the appropriate treatment for an
       individual, however, physicians have discretion to choose among a wide
       range of available options.
               It’s the theory of the defense that the Doctor Volkman, Doctor
       Paul H. Volkman, treated his patients in good faith. If a physician
       dispenses a drug in good faith in the course of medically treating a
       patient, then the doctor has dispensed the drug for a legitimate medical
       purpose in the usual course of accepted medical practice. That is, he has
       dispensed the drug lawfully.
              “Good faith” in this context means good intentions and an honest
       exercise of professional judgment as to a patient’s medical needs. It
       means that the defendant acted in accordance with what he reasonably
       believed to be proper medical practice.
              In considering whether the defendant acted with a legitimate
       medical purpose in the course of usual professional practice, you should
       consider all of the defendant’s actions and the circumstances
       surrounding them.
               ...
                The defendant does not have to prove to you that he acted in good
       faith; rather, the burden of proof is on the government to prove to you
       beyond a reasonable doubt that the defendant acted without a legitimate
       medical purpose outside the course of usual professional practice.

(DE 482, PageID 8589-90 (emphasis added).) The court capped off its explanation with
a discussion about the standard of care:

               You’ve heard the phrase “standard of care” used during the trial
       by several witnesses. When you go to see a doctor as a patient, the
       doctor must treat you in a manner that meets the applicable standard of
       care that physicians of similar training would have given to you under the
No. 12-3212        United States v. Volkman                                      Page 10


       same circumstances. If a doctor fails to provide you with that care, the
       doctor may be found neglect [sic] in a civil lawsuit.
              This case is not about whether the defendant acted negligently or
       whether he committed malpractice. Rather, in order for you to find the
       defendant guilty, you must find that the government has proved to you
       beyond a reasonable doubt that the defendant’s action was not for a
       legitimate medical purpose in the usual course of professional practice.

(DE 482, PageID 8590-91.)

       We conclude that these instructions amply and accurately conveyed the meaning
of “legitimate medical purpose” to the jury—the ultimate purpose of Volkman’s
proposed instruction. Not only were these instructions adequate to allay Volkman’s
concerns, they served as a model of clarity and comprehensiveness in defining the
unlawful-distribution offense for a case involving a so-called “pill mill” doctor. The
district court’s instructions appropriately defined the contours of the offense without
unduly cabining the jury’s ability to consider a broad swath of evidence in determining
whether Volkman’s conduct had no legitimate medical purpose. See United States v.
August, 984 F.2d 705, 713 (6th Cir. 1992) (“There are no specific guidelines concerning
what is required to support a conclusion that an accused acted outside the usual course
of professional practice.”). Hence, the district court properly rejected Volkman’s
proposed instruction.

                                          III.

       Next, we address Volkman’s argument that the district court improperly admitted
expert testimony containing a legal conclusion. We review a district court’s admission
of expert testimony for an abuse of discretion. In re Scrap Metal Antitrust Litig.,
527 F.3d 517, 528 (6th Cir. 2008). The evidentiary admission must be upheld unless the
district court “base[d] its ruling on an erroneous view of the law or a clearly erroneous
assessment of the evidence.” Best v. Lowe’s Home Ctrs., Inc., 563 F.3d 171, 176
(6th Cir. 2009) (quotation omitted).

       We accord district courts a “wide, but not unlimited, degree of discretion in
admitting or excluding testimony [that] arguably contains a legal conclusion.” United
No. 12-3212        United States v. Volkman                                      Page 11


States v. Nixon, 694 F.3d 623, 631 (6th Cir. 2012) (quoting Torres v. Cnty. of Oakland,
758 F.2d 147, 150 (6th Cir. 1985)) (internal quotation marks omitted). A witness’s
testimony contains a legal conclusion only if “the terms used by the witness have a
separate, distinct and specialized meaning in the law different from that present in the
vernacular.” Torres, 758 F.2d at 151. An expert may not opine on the overarching
question of guilt or innocence, but he or she may “stat[e] opinions that suggest the
answer to the ultimate issue or that give the jury all the information from which it can
draw inferences as to the ultimate issue.” Berry v. City of Detroit, 25 F.3d 1342, 1353
(6th Cir. 1994).

       Here, the controverted expert testimony followed a pattern.            First, the
Government would ask its expert witnesses about Volkman’s history with a particular
patient. After some back-and-forth about a patient’s condition and the prescriptions
Volkman dispensed, the Government would ask the expert whether he or she had an
opinion as to whether the prescriptions fell within the scope of legitimate medical
practice. The answer was typically no. Consider, for example, this exchange between
the prosecution and Dr. Douglas Kennedy:

       Q.      Doctor, do you have an opinion as to whether or not the
       prescriptions received from Dr. Volkman by Mr. Ratcliff back on
       October 21, 2005 were written within the scope of legitimate medical
       practice?
       A.     Absolutely not. They were not written for any legitimate medical
       purpose.

Volkman asserts that this type of testimony constituted an improper legal conclusion.

       We disagree, and join at least two of our sister circuits in doing so. The Seventh
Circuit’s decision in United States v. Chube II, 538 F.3d 693 (7th Cir. 2008), is
particularly persuasive. There, two doctors were convicted of unlawfully distributing
controlled substances. The Government introduced testimony by experts who concluded
that the doctors’ prescription practices did not conform to the “usual standards of
medical practice” and were devoid of a “legitimate medical purpose.” Id. at 697. A
typical colloquy between the Government and an expert went something like this:
No. 12-3212        United States v. Volkman                                       Page 12


       Q. [by the prosecution]: Doctor, would you like me to repeat the
       question?
       THE WITNESS: I believe I recall it pretty well . . . . It is never
       appropriate to write a prescription for the spouse of a patient when that
       prescription is intended for the patient; even more so when it’s a
       Schedule II narcotic . . . . It’s not consistent with the usual course of
       medical practice.
       Q. And that would not be for a legitimate medical purpose, correct?
       A. Correct.

Id. at 698. The court explained that “what the jury heard was . . . an opinion from the
expert that no legitimate medical purpose existed for the prescription in question.” Id.
(emphasis added). It concluded that the district court did not abuse its discretion in
allowing such testimony. Id. at 699. The Seventh Circuit was motivated by a practical
consideration: it observed that “it is impossible sensibly to discuss the question whether
a physician was acting outside the usual course of professional practice and without a
legitimate medical purpose without mentioning the usual standard of care.” Id. at 698.

       In United States v. Schneider, 704 F.3d 1287 (10th Cir. 2013), the Tenth Circuit
arrived at a similar conclusion. That case involved two doctors who were convicted of
unlawful drug distribution and health care fraud. The Government relied on experts who
testified that one of the defendants “prescribed controlled substances ‘for other than
legitimate medical purposes.’” Id. at 1294. Although the defendants challenged the
admission of this testimony, their arguments were unavailing. After observing that an
“ultimate-issue” concern only arises when “an expert uses a specialized legal term and
usurps the jury’s function,” the Tenth Circuit concluded that the experts’ use of the
phrase “other than legitimate medical purposes” posed no issue. Id.

       Much like the Government’s experts in Chube II, the experts in this case merely
provided opinions suggesting that Volkman had no legitimate medical purpose for
issuing a particular prescription to a specific patient. See Chube II, 538 F.3d at 699.
Certainly, there is the legal question of whether a prescription had a “legitimate medical
purpose,” but the question is hardly answered in isolation. Rather, the “lay” or, as we
No. 12-3212         United States v. Volkman                                      Page 13


have previously described it, “vernacular” understanding of the phrase—i.e., the phrase
as used in medical parlance—naturally informs the legal question. See id. at 698.
Therefore, the legal understanding of the phrase “legitimate medical purpose” does not
carry with it a “separate, distinct and specialized meaning” from its medical counterpart;
instead, one elucidates the other. See Torres, 758 F.2d at 151; see also Schneider,
704 F.3d at 1294. We discern no error in the district court’s admission of the expert
colloquies that ended with the conclusion that certain prescriptions had no “legitimate
medical purpose.”

       Two exchanges, however, are worthy of separate discussion. Dr. Steven Severyn
and an area pharmacist, Mark Carroll, provided a medical-purpose conclusion on the
stand, despite not having been asked about a particular individual’s prescriptions. But
even then, the questions were appropriately limited to the standard of care and the
evaluation of certain drug combinations or drug quantities. Nothing in the record
suggests that the two experts sought to usurp the jury’s function by drawing a legal
conclusion; instead, both experts applied their understanding of the standard-of-care to
a limited sample of facts. Accordingly, no error lies in the admission of their testimony.

                                           IV.

       At the heart of Volkman’s appeal lies six sufficiency-of-the-evidence challenges.
He contends that there was insufficient evidence for the jury to convict him on the
conspiracy and firearm charges; in addition, he argues that there was insufficient
evidence to convict him of the drug-induced deaths of Kristi Ross, Steven Craig
Hieneman, Bryan Brigner, and Earnest Ratcliff.

       In reviewing these convictions, we ask whether, “after construing the evidence
in favor of the Government, no rational trier of fact could have found the essential
elements of a crime beyond a reasonable doubt.” United States v. Ross, 703 F.3d 856,
882 (6th Cir. 2012). The standard is a “steep climb,” id. (quotation omitted), and
circumstantial evidence alone can defeat a sufficiency challenge, United States v.
Washington, 702 F.3d 886, 891 (6th Cir. 2012).
No. 12-3212         United States v. Volkman                                      Page 14


                                             A.

        We start with Volkman’s conviction under 21 U.S.C. § 846—the conspiracy
charge. To satisfy the statute’s requirements, “the government must prove the existence
of an agreement to violate the drug laws and that each conspirator knew of, intended to
join, and participated in the conspiracy.” United States v. Conrad, 507 F.3d 424, 432
(6th Cir. 2007) (quotation omitted). “The connection between the defendant and the
conspiracy need only be slight,” United States v. Craft, 495 F.3d 259, 265 (6th Cir.
2007) (quoting United States v. Crayton, 357 F.3d 560, 573 (6th Cir. 2004)), and a
“conspiracy may be inferred from circumstantial evidence which may reasonably be
interpreted as participation in a common plan,” Conrad, 507 F.3d at 432 (quotation
omitted). In addition, “[a] tacit or material understanding among the parties to a
conspiracy is sufficient to establish the agreement.” Id. (quotation omitted).

        Volkman claims that he had no knowledge of the conspiracy’s “main
purpose”—“to make as much money as possible by distributing and dispensing
controlled substances.” Instead, he asserts that he was hired with the sole understanding
that he would be serving as a pain management physician. The clinic was, in the ex-
doctor’s view, a legitimate medical operation—complete with in-house and hospital drug
screens, pill counts, and in-clinic monitoring of patients. According to Volkman, an
illicit, drug-based profit motive did not fit into the big picture.

        His recollection of events, however, turns a blind eye to quite a bit of
evidence—evidence that supports his conspiracy conviction.            The conspiratorial
relationship began when Denise hired Volkman and paid him $5,500 per week in
exchange for seeing those who wanted pain medication. There was evidence to suggest
that, by the time area physicians began refusing to fill Volkman’s prescriptions, the
purported members of the conspiracy—Denise, Alice, and Volkman—were aware of the
reality that the prescriptions from their clinic had no legitimate medical purpose. Instead
of rectifying the pharmacists’ issues with Volkman’s prescriptions, the trio exacerbated
the problem by continuing to issue prescriptions, cutting out the middleman, and opening
No. 12-3212         United States v. Volkman                                       Page 15


their own dispensary. This, by itself, was enough for a jury to find that the trio executed
a plan to unlawfully distribute controlled substances with no legitimate medical purpose.

        And contrary to his assertions, there was sufficient evidence to show that
Volkman was hardly the blissfully-ignorant doctor he now makes himself out to be. A
rational trier of fact could have easily concluded that the entire enterprise of dispensing
pills straight from the clinic was Volkman’s brainchild. That same trier of fact could
have determined it was highly unlikely that Volkman—a man who prided himself on
knowing the inner workings of his clinic—was unaware of the clinic’s profits. All this,
combined with Volkman’s role in rubber-stamping the distribution of prescriptions,
could have easily persuaded a jury that Volkman knew of and actively participated in the
charged conspiracy.

                                            B.

        The same holds true for Volkman’s firearm conviction. He argues that there was
insufficient evidence to convict him of possessing a firearm in furtherance of a drug-
trafficking crime because (1) the Government did not establish possession; and (2) it did
not prove that the weapon was used in furtherance of a drug-trafficking offense. We
disagree.

        First, we address the question of possession. For purposes of the firearms statute,
“[c]onstructive possession is established when a defendant ‘knowingly has the power
and the intention at a given time to exercise dominion and control over an object, either
directly or through others.’” United States v. Kelsor, 665 F.3d 684, 692 (6th Cir. 2011)
(quoting United States v. Hadley, 431 F.3d 484, 507 (6th Cir. 2005)). Here, there was
evidence showing that Alice’s father placed the gun in the safe containing the drugs “for
security purposes.” Volkman had access to the safe. The record also reveals that he had
concerns about personal security, giving him a reason to use the gun should the need
arise. Video evidence confirms that the Glock was in the safe in 2005; Volkman was
still working at the clinic at the time. This was sufficient for a rational trier of fact to
conclude that Volkman constructively possessed the firearm for which he was indicted
and convicted.
No. 12-3212        United States v. Volkman                                       Page 16


       But that does not end our inquiry, for Volkman argues that even if he
constructively possessed the firearm, the fact that it was in a locked safe meant that the
weapon was not possessed in furtherance of a drug crime, given its immediate
inaccessibility. We, however, have concluded otherwise in the past. When a weapon
is found in a locked safe placed alongside contraband, there is sufficient evidence for a
jury to determine that a defendant is in possession of a firearm in furtherance of a drug-
trafficking crime. See United States v. Mendizabal, 214 F. App’x 496, 501 (6th Cir.
2006); see also United States v. Cobbs, 233 F. App’x 524, 535-36 (6th Cir. 2007)
(concluding that there was sufficient evidence for a jury to find that a locked safe with
four handguns and crack cocaine nearby the safe constituted possession of a firearm in
furtherance of a drug offense). Hence, Volkman’s challenge to his firearm conviction
must fail.

                                           C.

       The most serious of Volkman’s convictions are the ones for unlawful distribution
of a controlled substance leading to death. Volkman contends that a rational trier of fact
could not conclude that his prescription practices resulted in the deaths of Kristi Ross,
Steve Hieneman, Bryan Brigner, and Earnest Ratcliff.

       A violation of the Controlled Substances Act (CSA) occurs when a physician
dispenses or distributes a controlled substance in a manner that is not authorized by
law—i.e., the prescription is issued by a physician without “a legitimate medical purpose
by an individual practitioner acting in the usual course of his professional practice.”
Kirk, 584 F.2d at 784 (quoting 21 C.F.R. § 1306.04(a)); see also 21 U.S.C. § 841(a)(1).
To determine whether a physician has violated the CSA, the jury may undertake a “case
by case analysis of evidence to determine whether a reasonable inference of guilt may
be drawn from specific facts.” Kirk, 584 F.2d at 784. When a physician violates the
CSA in a manner that leads to the death of a patient, there is a mandatory sentence of
twenty years to life in prison. See 21 U.S.C. § 841(b)(1)(C) (2000).

       With respect to the deaths of the four individuals, there was sufficient evidence
for a jury to conclude that (1) Volkman issued a prescription; (2) that had no legitimate
No. 12-3212         United States v. Volkman                                        Page 17


medical purpose; (3) which resulted in death. Thus, the Government satisfied its burden
of proof under the CSA. While Volkman tries to dispute some aspect of each conviction,
we are unpersuaded by his arguments.

                                             1.

        First, we have Kristi Ross. On March 8, 2004, Ross—an obese, 39-year-old
woman—came into Volkman’s office, complaining of low back pain, cervical myalgia,
and hypertension. Her pending divorce and her husband’s efforts to take custody of their
daughter compounded her stress. Volkman prescribed a cocktail of Soma (carisoprodol),
Lorcet (hydrocodone), oxycodone, and Xanax (alprazolam).

        Ross, however, suffered from a number of risk factors. In addition to her
hypertension and obesity, she potentially suffered from sleep apnea, as well as some
form of lung disorder. In other words, she was already at risk of breathing difficulties,
and Volkman’s drug cocktail exposed her to a greater risk of death. A rational trier of
fact, relying on expert testimony, could have found that there was no legitimate medical
purpose for this combination of drugs.

        On March 9, 2004—a day after her last visit to Volkman—Ross was found dead,
with the very drugs prescribed to her. A toxicology report revealed that, at the time of
her death, Ross had benzodiazepines and opiates in her system—a toxic combination
“consistent with [Volkman’s] prescriptions.” An expert concluded that Ross died of a
multi-drug death. The trier of fact had sufficient evidence to conclude that Volkman’s
unlawful prescriptions led to Ross’ death, thus justifying the conviction under
§ 841(b)(1)(C).

        Volkman takes issue with the accuracy of the post-mortem procedures used on
Ross’ body—specifically, he argues that fluids should have been extracted from Ross’
femoral artery, as opposed to her eye. While this argument may be perfectly valid, we
are not in a position to entertain it; it is for the jury to decide which evidence—scientific
or otherwise—to credit in making its determination. United States v. Washington,
715 F.3d 975, 979 (6th Cir. 2013) (citing Jackson v. Virginia, 443 U.S. 307, 319 (1979)).
No. 12-3212        United States v. Volkman                                      Page 18


It was well within the jury’s ambit for it to find the methodology behind Ross’ forensics
reliable.

                                            2.

        Next, we have Steven Craig Hieneman. Hieneman was a 33-year-old man with
cardiovascular problems. Hieneman had seen Volkman as a patient for quite some
time—the doctor had prescribed oxycodone in the past, mostly in five-milligram doses.
Eventually, these doses of oxycodone were ramped up to thirty-milligram doses.
Hieneman saw Volkman on February 22, 2005, complaining of pain in his wrist, neck,
lower back, and shoulder. Hieneman reported that, without medication, he was sleep-
deprived, convulsed involuntarily in his hand and shoulder, and his pain was above
average.

        That day, Volkman prescribed Disalcid, Valium (diazepam), and Percocet
(oxycodone) to treat Hieneman’s ailments. On April 19, 2005, Volkman changed
Hieneman’s prescriptions—he issued prescriptions for Xanax (alprazolam), oxycodone,
and Valium (diazepam). The prescriptions, particularly the one for oxycodone, were
disturbing in light of the fact that Hieneman had a past addiction to Oxycontin and was
battling other forms of substance abuse.

        Volkman knew about Hieneman’s history, yet issued prescriptions for
oxycodone. In addition, the doctor knew he was prescribing these drugs to a man with
severe hypertension and heart problems associated with drug use. Given these dangers,
a rational trier of fact could have concluded—as one of the Government’s experts
did—that Volkman’s prescription practices with respect to Hieneman were not within
the scope of legitimate medical practice.

        In addition, there was sufficient evidence to draw a causal connection between
Hieneman’s prescriptions and his death. Hieneman died twelve hours after receiving his
prescriptions from Volkman. Although there was no autopsy, a deputy coroner
concluded that Hieneman died an opiate drug-induced death. The signs were all there:
Hieneman’s right cheek was blanched, his airways were partly blocked, his eyes were
No. 12-3212        United States v. Volkman                                      Page 19


hemorrhaged under the conjunctivae, and he suffered from pulmonary edema. The link
to Volkman?      Bottles of oxycodone, diazepam, and alprazolam were found in
Hieneman’s home—i.e., the very drugs Volkman prescribed to Hieneman the day before.

       Volkman argues that those very prescription bottles undermine the case against
him: the issuing doctor for one bottle of oxycodone was identified as a Dr. Lance, not
Volkman. But there was sufficient evidence for the jury to discredit the theory that it
was Lance, and not Volkman, who was ultimately responsible for Hieneman’s death.

       First, Volkman’s patient notes acknowledged the existence of a Dr. Scott Lance
as a prescribing physician for Hieneman, but marked that Lance had prescribed only
Valium (diazepam). Relatedly, the notes indicated that Hieneman no longer had any of
the medication Lance prescribed for him; it was gone at least a month prior to
Hieneman’s February 2005 visit to Volkman’s clinic.

       Second, while one bottle of oxycodone was labeled as having been prescribed
by Dr. Lance, the other bottles found at the scene did not have a prescribing physician
listed. Finally, there was a close temporal nexus between Volkman’s issuing of
prescriptions and Hieneman’s death; the relevance of this nexus is strengthened by the
fact that Hieneman was found dead with the very drugs the doctor prescribed.
Therefore, we conclude that the Government provided sufficient causal evidence to link
Volkman to Hieneman’s death.

       We are unpersuaded by Volkman’s argument that Hieneman’s underlying heart
condition could have caused his death, irrespective of the drugs he consumed. The jury
was free to reject this theory by crediting the testimony of one of the Government’s
experts, who concluded that “there was no notation of clot, no notation of infarct, scar,
plaque, hemorrhage or anything like that,” thereby suggesting that coronary disease was
not the primary cause of Hieneman’s death. Thus, we conclude that there was sufficient
evidence for a rational trier of fact to find that Volkman was responsible for unlawful
distribution leading to Hieneman’s death.
No. 12-3212        United States v. Volkman                                       Page 20


                                            3.

       Following Hieneman, we have Bryan Brigner. On August 4, 2005, Brigner came
to see Volkman for treatment of his lower back pain. Brigner was disabled and had been
on disability benefits for several years. When Volkman spoke with Brigner, Brigner
denied having any other health problems. In truth, however, Brigner suffered from
hypertension and arteriosclerotic cardiovascular disease.

       When the two met that August day, Brigner was already on a regimen of Lortab
(hydrocodone), oxycodone, Valium (diazepam), and Soma (carisoprodol).                 The
oxycodone made him sick, so Volkman tried a smaller dose—but not for long. On
September 30, 2005, Volkman prescribed a similar cocktail of Soma (carisoprodol),
Valium (diazepam), Disalcid (a non-steroidal anti-inflammatory drug), Lortab
(hydrocodone), and a strong dose of oxycodone. The oxycodone prescription was for
the same dose that made Brigner sick prior to his August visit.

       The new cocktail made little sense, especially given Brigner’s underlying cardiac
condition—a condition that weakened his ability to resist opiate toxicity. Volkman’s
notes on Brigner were also unhelpful; as one expert noted, it appeared as if there was “a
lot of stuff . . . but really the basics [weren’t] covered in a useful, functional, medical
fashion, just a bunch of stuff that’s thrown up there.” A rational trier of fact could have
taken these facts and concluded that Volkman’s prescriptions for Brigner did not bear
the hallmarks of having a legitimate medical purpose.

       As with Ross and Hieneman, Brigner was found dead a couple days after his last
visit with Volkman. Two causes of death were listed on the coroner’s report: acute
multiple drug intoxication and cardiopulmonary arrest. Brigner’s hypertension and
arteriosclerotic cardiovascular disease were reported as contributing factors.           A
toxicology analysis revealed that Brigner had taken oxycodone, hydrocodone, diazepam,
haloperidol, and Sertraline just prior to his death. The first three—the drugs prescribed
by Volkman—were enough to kill a person by respiratory depression. Put differently,
there was enough for a rational jury to conclude that Volkman’s drug cocktail led to
Brigner’s death.
No. 12-3212        United States v. Volkman                                       Page 21


       Despite this evidence, Volkman attacks his conviction on three evidentiary
grounds. First, he claims that if Brigner had taken Volkman’s prescribed medication as
instructed, he would not have overdosed because he would have built up a tolerance.
Second, he asserts that Sertraline and haloperidol—two drugs that Volkman did not
prescribe but found in Brigner’s system—could have been responsible for Brigner’s
death. Third, he argues that underlying heart conditions, such as cardiomegaly (an
enlarged heart) or unstable plaque could have triggered the cardiac incident leading to
Brigner’s death.

       For each one of these assertions, there is an evidentiary counterweight. First, a
rational jury could have credited Dr. Castro’s testimony that, of “[t]he medications
. . . included with [Brigner], none of them would give him opiate tolerance.” Second,
while the evidence did suggest that Sertraline and haloperidol can be lethal, they are only
toxic in high doses. The trier of fact could have concluded that the levels in Brigner’s
bloodstream were too low to support such a theory. Finally, given the fact that there
were no signs of a myocardial infarction—the usual indicator of complications arising
from arteriosclerotic cardiovascular disease—a rational trier of fact was not compelled
to accept Volkman’s argument that an underlying condition led to Brigner’s death.
Hence, we affirm this conviction.

                                            4.

       Finally, we have Earnest Ratcliff. Ratcliff was a 38-year-old man suffering from
pain in his back, ankles, and feet. He had a history of drug addiction and minor drug
dealing.

       Volkman saw Ratcliff on October 21, 2005. The doctor issued prescriptions for
240 thirty-milligram doses of oxycodone, 90 doses of Soma (carisoprodol), 240 doses
of Lortab (hydrocodone), and 90 doses of Xanax (alprazolam)—660 pills in all. Given
the sheer drug quantity alone, a rational trier of fact could have concluded that there was
no legitimate medical purpose to the prescriptions, given the risk that Ratcliff would not
comply with drug protocol and the attendant risk of an adverse outcome.
No. 12-3212         United States v. Volkman                                      Page 22


         The next day, Ratcliff and his wife Melissa went to pick up the drugs from a
drugstore in Columbus. After obtaining the drugs, he proceeded to consume—or more
exactly, snort—the pills on the way home. Ratcliff was lethargic and asleep for most of
the drive. His wife found his behavior unusual, in light of his past history with the
drugs.

         Mrs. Ratcliff found her husband dead the next morning. He died two days after
his visit to Volkman’s office. No autopsy was performed, but a toxicology report
revealed that oxycodone, methadone, hydrocodone, diazepam, and nordiazepam were
in his bloodstream. From this, a rational trier of fact had a sufficient evidentiary basis
for concluding that Ratcliff’s death—caused by “multi-drug intoxication”—was
Volkman’s fault.

         Volkman argues that the methadone alone could have been lethal. Methadone,
of course, was the one drug that he did not prescribe. Indeed, he points out that one of
the Government’s own experts testified that the methadone was “very significant” in
Ratcliff’s death.

         There was enough evidence, however, for a jury to disregard the possibility that
methadone acted as the lone lethal agent. First, it was a cumulative effect of toxicity,
not a single drug, that was responsible for Ratcliff’s death. Second, Ratcliff took
methadone earlier in the week—prior to taking the drugs that Volkman gave him—and
was functional after consuming the methadone. A jury could have used this as the basis
for excluding the possibility that methadone alone was responsible for Ratcliff’s death.
Finally, a rational trier of fact could have credited the testimony of the toxicologist who
examined Ratcliff’s blood and agreed with her conclusion that oxycodone, not
methadone, was most significant in his death. Hence, we conclude that there was
sufficient evidence to support Volkman’s conviction for unlawful distribution leading
to the death of Earnest Ratcliff.
No. 12-3212        United States v. Volkman                                      Page 23


                                           V.

       The final salvo of Volkman’s appeal attacks the reasonableness of his sentence.
“This Court reviews criminal sentences for both substantive and procedural
reasonableness,” and uses the “deferential abuse-of-discretion standard” to determine the
propriety of the sentence. United States v. Stubblefield, 682 F.3d 502, 510 (6th Cir.
2012) (citing Gall v. United States, 552 U.S. 38, 51 (2007); United States v. Battaglia,
624 F.3d 348, 350 (6th Cir. 2010)).

       Two of Volkman’s sentencing arguments focus on the district court’s application
of certain Guidelines enhancements. Volkman also disputes the district court’s drug-
quantity determination. We construe these contentions as procedural reasonableness
challenges. See Stubblefield, 682 F.3d at 510; see also United States v. Daniels, 506 F.
App’x 399, 399 (6th Cir. 2012) (treating a drug-quantity objection as a procedural-
reasonableness issue). As for Volkman’s sentencing-disparity argument, we view that
as a substantive reasonableness challenge. See United States v. French, 505 F. App’x
478, 479-80 (6th Cir. 2012).

                                           A.

       Volkman first takes issue with the district court’s application of the vulnerable-
victim enhancement. He asserts that the district court improperly based the enhancement
on his victims’ status as drug addicts.

       Section 3A1.1(b) of the Sentencing Guidelines provides for a two-level
enhancement in instances where “the defendant knew or should have known that a
victim of the offense was a vulnerable victim.” The Application Notes, however, state
that the victim must be “an unusually vulnerable victim.” U.S. Sentencing Guidelines
Manual § 3A1.1(b) cmt. n.2 (emphasis added).

       In the past, we have acknowledged a tension between the Guideline language and
the Application Notes. See United States v. Lukasik, 250 F. App’x 135, 138 (6th Cir.
2007). We need not resolve that tension today, however, because Volkman’s conduct
fell within the parameters of both.
No. 12-3212        United States v. Volkman                                       Page 24


        We agree with Volkman in concluding that drug addiction, standing alone,
cannot serve as the basis for applying the enhancement in cases such as this one. Drug
addicts are not necessarily vulnerable victims for purposes of section 3A1.1, and we
decline to categorically classify them as such. See United States v. Amedeo, 370 F.3d
1305, 1317 n.10 (11th Cir. 2004).

        But the circumstances of this case nevertheless support application of the
enhancement. See id. (noting that application of the enhancement is “highly fact-specific
and must take into account the totality of the circumstances”). It is true that the Pre-
Sentence Investigation Report, as well as the Government’s arguments at sentencing,
focused heavily on the victims’ drug addiction. If this had been the sole basis for the
district court’s decision to apply the enhancement, then reversal would be warranted.

        The court, however, made additional findings regarding specific victims’
ailments. It noted the mental and emotional frailties of some of Volkman’s patients by
stating that “[s]ome patients had serious psychiatric problems[,] [s]ome even had prior
suicide attempts.” The court made these observations based on statements that Volkman
made during the sentencing proceedings. We will not overturn a district court’s fact
findings unless they are clearly erroneous. See United States v. Moon, 513 F.3d 527,
539-40 (6th Cir. 2008). These fact findings were not clearly erroneous. Under either the
Guideline or its accompanying note, the findings were sufficient to justify application
of the vulnerable-victim enhancement.         See U.S. Sentencing Guidelines Manual
§ 3A1.1(b) cmt. n.2 (“[V]ulnerable victim means a person . . . who is unusually
vulnerable due to . . . mental condition[.]”). Therefore, we discern no abuse of discretion
here.

                                            B.

        Because we conclude that application of the vulnerable-victim enhancement was
proper, we must next address Volkman’s argument that applying both that enhancement
and the special-skill enhancement was impermissible double counting. Such double
counting occurs when “precisely the same aspect of the defendant’s conduct is factored
into his sentence in two separate ways.” United States v. Lay, 583 F.3d 436, 447 (6th
No. 12-3212           United States v. Volkman                                       Page 25


Cir. 2009) (quoting United States v. Farrow, 198 F.3d 179, 193 (6th Cir. 1999))
(quotation marks and modifications omitted). “We review a district court’s legal
conclusions regarding the Sentencing Guidelines de novo.” Moon, 513 F.3d at 540
(citation omitted).

        The two enhancements at issue focus on different aspects of the case. Courts
apply the special-skill enhancement when a “defendant . . . use[s] a special skill, in a
manner that significantly facilitate[s] the commission or concealment of the offense.”
U.S. Sentencing Guidelines Manual § 3B1.3. A special skill is defined as “a skill not
possessed by members of the general public and usually requiring substantial education,
training or licensing.” Id. § 3B1.3 cmt. n.4. The Guideline notes specifically list doctors
as one group of individuals possessing special skills. Id. In contrast—and as the district
court properly noted—the vulnerable-victim enhancement focuses on the nature of the
victim, as opposed to the offender. See id. § 3A1.1(b) cmt. n.2.

        The fact that a defendant is a doctor—and his victim a patient—is insufficient
for applying the vulnerable-victim enhancement. See United States v. Stokes, 392 F.
App’x 362, 371 (6th Cir. 2010) (“[T]he traditional doctor-patient relationship, on its
own, provides an insufficient basis for applying the vulnerable-victim enhancement.”).
It is, however, sufficient for applying the special-skill enhancement, especially in light
of the fact that Volkman would not have been in a position to abuse his prescription
power without his medical license. See 21 U.S.C. § 823(f) (detailing the CSA’s
registration requirements); see also id. § 802(21) (defining “practitioner”); United States
v. Moore, 423 U.S. 122, 140 n.17 (1975).              Given the differences in how the
enhancements apply, we discern no impermissible double-counting here.

                                             C.

        We can readily dispose of Volkman’s remaining arguments. First, Volkman
argues that the district court did not account for legitimate prescriptions in arriving at its
drug-quantity determination. Even if we assume that the district court erred by
concluding that Volkman’s drug-quantity determination warranted a base offense level
of 38, such an error would be harmless. Volkman’s convictions for unlawful distribution
No. 12-3212        United States v. Volkman                                      Page 26


leading to death, standing alone, warrant the same base offense level. See U.S.
Sentencing Guidelines Manual § 2D1.1(a)(2) (specifying a base offense level of 38 “if
the defendant is convicted [under § 841(b)(1)(C)] . . . and the offense of conviction
establishes that death or serious bodily injury resulted from the use of the substance”).
Consequently, we could not reverse on this ground. See United States v. Tandon,
111 F.3d 482, 491 (6th Cir. 1997) (holding that a tax-loss calculation error was harmless
because the base offense level would be unaffected).

       We are equally unpersuaded by Volkman’s sentencing-disparity argument. Four
life sentences, one for each § 841(b)(1)(C) conviction, may appear relatively disparate.
Other doctors in a similar position may have been sentenced to a less lengthy term of
imprisonment.    But each of Volkman’s life sentences fell within the applicable
Guidelines ranges. When a sentence is within-Guidelines, § 3553(a)(6) is an improper
vehicle for challenging that sentence. See United States v. Swafford, 639 F.3d 265, 270
(6th Cir. 2011). Thus, we conclude that Volkman’s sentence was substantively
reasonable.

                                          VI.

       We AFFIRM Volkman’s convictions and sentence.
