  United States Court of Appeals
      for the Federal Circuit
                ______________________

                JEFFREY A. HANSEN,
                     Petitioner

                           v.

    DEPARTMENT OF HOMELAND SECURITY,
                 Respondent
           ______________________

                      2017-2584
                ______________________

   Petition for review of the Merit Systems Protection
Board in No. DE-0752-17-0076-I-1.
                ______________________

              Decided: December 28, 2018
               ______________________

    MICHAEL J. KATOR, Kator, Parks, Weiser & Harris
P.L.L.C., Washington, DC, argued for petitioner. Also
represented by DANIEL R. CLARK; JEREMY D. WRIGHT,
Austin, TX.

    DOUGLAS G. EDELSCHICK, Commercial Litigation
Branch, Civil Division, United States Department of
Justice, Washington, DC, argued for respondent. Also
represented by LISA L. DONAHUE, ROBERT E. KIRSCHMAN,
JR., JOSEPH H. HUNT; MILI R. SMITH, Office of the Associ-
ate Chief Counsel, United States Customs and Border
Protection, Chicago, IL.
2                                             HANSEN v. DHS




    DEBRA A. D’AGOSTINO, The Federal Practice Group
Worldwide Service, Washington, DC, for amicus curiae
Metropolitan Washington Employment Lawyers Associa-
tion.
               ______________________

    Before O’MALLEY, CHEN, and STOLL, Circuit Judges.
STOLL, Circuit Judge.
    Following a positive drug test, the Department of
Homeland Security removed Jeffrey Hansen from his
position as an Information Technology Specialist for U.S.
Customs and Border Protection. The Merit Systems
Protection Board affirmed the agency’s decision.
Mr. Hansen now appeals, arguing that the Board improp-
erly assigned him the burden of proving that he inadvert-
ently ingested marijuana, that it erred in finding his
position was subject to random drug testing, and that
even if it was subject to such testing, he lacked required
notice of that fact.
    We hold that intent is not an element of the charged
conduct and that the Board properly required Mr. Hansen
to introduce rebuttal evidence to counter the govern-
ment’s showing of nexus and choice of penalty. We also
determine that substantial evidence supports the Board’s
finding that Mr. Hansen’s position was designated for
random drug testing. Because Mr. Hansen’s remaining
arguments are either unpersuasive or waived, we affirm
the Board.
                        BACKGROUND
    Mr. Hansen’s supervisor directed him to report for a
random drug test. He did so, but failed, testing positive
for marijuana. J.A. 99. Mr. Hansen never contested the
accuracy of the test result, J.A. 103, but he contended that
he had not knowingly used marijuana, averring that he
HANSEN v. DHS                                            3



had “never used any illegal substance and was shocked
when [he] got this call,” J.A. 102.
    After failing the drug test, Mr. Hansen submitted a
letter to the agency. In it, he posited that he had inad-
vertently consumed drug-laced brownies at a barbeque a
few days before his failed test. J.A. 100. Mr. Hansen
claimed that a friend-of-a-friend’s neighbor, a stranger to
him, had hosted the barbeque. Upon failing the drug test,
Mr. Hansen explained, he informed his friends that he
had “tested positive and would probably lose [his] job,”
and he then learned that some unknown person “at the
[barbeque] thought it would be funny to bring [marijuana-
laced] brownies.” Id.
    Shortly after Mr. Hansen submitted his letter, the
agency issued a Notice of Proposed Removal, explaining
that “[t]he use of an illegal drug, such as marijuana,
stands in direct conflict with the principles of law en-
forcement, the mission of the Agency, and the public’s
trust.” J.A. 25. Mr. Hansen then submitted a second
letter of explanation, maintaining that he had inadvert-
ently consumed marijuana in brownies at the barbeque.
He provided an affidavit from the lifelong friend who had
invited him, who stated that although “an attendee did
indeed bring ‘pot brownies,’” “neither I nor my friends
that invited us knew.” J.A. 107. Neither Mr. Hansen nor
his friend identified the person who had provided the
brownies or who had the hosted the barbeque.
    The deciding official gave Mr. Hansen’s explanation
and evidence “significant consideration” but found it
unconvincing. J.A. 19–20. She noted that the only evi-
dence that marijuana-laced brownies were even available
at the barbeque came from Mr. Hansen’s friend—whose
only knowledge derived from a phone call with the un-
named host. She emphasized that Mr. Hansen did not
provide “any evidence from either the person who pur-
portedly brought the brownies, or from the host” or even
4                                           HANSEN v. DHS




“a statement from anyone else who either knew that the
brownies contained marijuana or who did not know, but
felt the effect of the drug.” J.A. 20. And she questioned
how, although Mr. Hansen stated that he did not drink
alcohol and preferred to avoid even prescribed medica-
tions, he “experienced no behavioral or physiological
effects of the drug.” Id. The deciding official thus sus-
tained a charge of “positive test for illegal drug use—
marijuana,” and removed Mr. Hansen from his position.
Mr. Hansen then appealed to the Board.
    Before the Board, Mr. Hansen submitted additional
details regarding the barbeque. He reported that the
backyard barbeque took place in early April in Minnesota,
where the temperature was in the 30s. Mr. Hansen
stated that while at the barbeque, he consumed a brat-
wurst outside, then briefly entered the host’s home, ate
two unlabeled, frosted brownies in quick succession, and
then rejoined the party. Mr. Hansen also revealed that
though he felt no immediate effects from the brownies,
later that evening he felt tired and suffered an upset
stomach, which he attributed to the bratwurst, and the
next day, he called in sick to work.
    After reviewing the evidence, the Board affirmed the
agency’s removal decision. After first concluding that
Mr. Hansen was subject to random drug testing, the
Board held that the government had “met its burden of
showing, by preponderant evidence” that Mr. Hansen had
committed the charged misconduct, discipline was war-
ranted, and the penalty was reasonable. J.A. 13. The
Board acknowledged that inadvertent ingestion would be
relevant to its decision, if shown. But it determined that
Mr. Hansen, not the government, bore the “burden of
showing such inadvertent ingestion,” reasoning that
Mr. Hansen held the relevant facts and that past cases
declining to penalize inadvertent drug use implicitly
relied on findings that the employee had proven inadvert-
ent use. J.A. 9–10.
HANSEN v. DHS                                              5



    Considering the evidence of inadvertence introduced
by Mr. Hansen, the Board found that he failed to “pre-
sent[] sufficient proof of inadvertent ingestion to warrant
interfering” with the agency’s removal decision. J.A. 10.
The Board explained that Mr. Hansen relied on “third-
hand hearsay” to support his story and had not supplied
“statements from the hosts, other attendees who observed
the presence of the brownies, or the individuals who
brought the brownies,” or even evidence confirming that
he ate brownies. J.A. 11. It further noted that though
Mr. Hansen claimed fatigue and upset stomach after
consuming the brownies, he attributed those ailments to
marijuana consumption only after the deciding official
expressed skepticism regarding his lack of symptoms.
Even accepting that marijuana consumption might pro-
duce the symptoms Mr. Hansen belatedly reported, the
Board credited expert testimony that fatigue and upset
stomach might occur for many other reasons. It therefore
concluded that the government had met its burden, “in
significant part” because Mr. Hansen did not prove his
inadvertent ingestion theory. J.A. 13. Mr. Hansen ap-
peals, and we have jurisdiction. 28 U.S.C. § 1295(a)(9).
                        DISCUSSION
     We review the Board’s legal conclusions de novo and
its fact findings for substantial evidence. See Campbell v.
Merit Sys. Prot. Bd., 27 F.3d 1560, 1564 (Fed. Cir. 1994).
We may reverse the Board only if its decision is
“(1) arbitrary, capricious, an abuse of discretion, or other-
wise not in accordance with law; (2) obtained without
procedures required by law, rule, or regulation having
been followed; or (3) unsupported by substantial evi-
dence.”     Cobert v. Miller, 800 F.3d 1340, 1347–48
(Fed. Cir. 2015).
                              I
   We first consider whether the Board properly held the
government to its burden of proof. Before removing an
6                                             HANSEN v. DHS




employee, the government must prove by preponderant
evidence that: (1) the charged misconduct occurred,
(2) there is a nexus between what the employee did and
disciplining the employee to promote the efficiency of the
service, and (3) the particular penalty is reasonable. See
Pope v. U.S. Postal Serv., 114 F.3d 1144, 1147 (Fed. Cir.
1997); see also Hale v. Dep’t of Transp., 772 F.2d 882, 885
(Fed. Cir. 1985). The burden of proof never shifts from
the government, but once the government presents evi-
dence tending to establish each of these elements, “the
burden of going forward with evidence to rebut that
showing necessarily shifts to the employee, who is in the
best position to present explanatory evidence to counter
that showing.” Schapansky v. Dep’t of Transp., 735 F.2d
477, 482 (Fed. Cir. 1984); see also Allred v. Dep’t of Health
& Human Servs., 786 F.2d 1128, 1131–33 (Fed. Cir. 1986)
(sustaining removal where employee failed to rebut nexus
and failed to rebut reasonableness of penalty). Taking
into account all of the facts and circumstances, the Board
must then determine whether the government has met its
burden. See Schapansky, 735 F.2d at 482–83.
    Extrapolating from cases in which this court and the
Board have reversed removal where an employee inad-
vertently ingested drugs, Mr. Hansen argues that by
requiring him to show inadvertent ingestion, the Board
misplaced the burden of proof. Pet’r’s Br. 2, 9–10.
Mr. Hansen assumes that intent is either an element of a
“positive test” charge or a fact the government must prove
to show a nexus between the misconduct and the efficien-
cy of the service or to prove the reasonableness of a par-
ticular penalty. We disagree. The government had no
need to prove intent to establish that Mr. Hansen com-
mitted misconduct warranting removal.
    Mr. Hansen’s undisputedly positive test result suf-
ficed to prove the charge of “positive test for illegal drug
use—marijuana.” Under agency policy, a positive drug
test suffices to find illegal drug use and constitutes mis-
HANSEN v. DHS                                              7



conduct. See J.A. 50, 89. As the Board found, under that
policy, the government need only show a positive drug
test to sustain a “positive test” charge. See J.A. 7–8.
Though Mr. Hansen might prefer that the agency adopt a
different policy, he does not challenge (and we do not
decide), the existing policy’s permissibility. See J.A. 103;
see also Baird v. Dep’t of the Army, 517 F.3d 1345, 1351
(Fed. Cir. 2008) (noting without deciding that an agency
“may be free to adopt and enforce . . . [a] policy pursuant
to which any [testing designated position] employee who
refuses to submit to or fails a drug test, will be removed”).
We thus decline his invitation to “inject[] an intent re-
quirement” into the charged misconduct. See King v.
Frazier, 77 F.3d 1361, 1363 (Fed. Cir. 1996). 1
    Similarly, the government did not need to prove in-
tent to establish that Mr. Hansen’s misconduct impacted
the efficiency of the service or that it reasonably removed
him. Mr. Hansen agrees that “illegal drug use by a [Cus-
toms and Border Protection] employee is in direct conflict
with the principles of law enforcement, the mission of the
agency and the public’s trust.” J.A. 103 (emphasis added).
And though the Board must consider any evidence of



    1    We emphasize, however, that, unlike here, where
intent is an element of the misconduct charged, the gov-
ernment must prove intent. See Chauvin v. Dep’t of the
Navy, 38 F.3d 563, 565–66 (Fed. Cir. 1994) (sustaining
“unauthorized possession” charge but finding government
failed to prove “attempted removal” charge because it
failed to show intent, “an important element of proof in an
‘attempt’ charge”); King v. Nazelrod, 43 F.3d 663, 665–66
(Fed. Cir. 1994) (explaining government must prove
intent for theft charge because “one of the elements of
theft is the intent to permanently deprive the owner of
possession”).
8                                              HANSEN v. DHS




inadvertence in its reasonableness inquiry as part of the
analysis mandated by Douglas v. Veterans Administra-
tion, 5 M.S.P.B. 313 (1981), it does not follow that it is the
government’s burden to introduce evidence of intent to
prove reasonableness. “We have not required that each
and every factor of the twelve Douglas factors be consid-
ered. We have only required that the penalty selected be
reasonable when considered against the relevant factors.”
Brennan v. Dep’t of Health & Human Servs., 787 F.2d
1559, 1563 (Fed. Cir. 1986); see also Jones v. U.S. Postal
Serv., 502 F. App’x 930, 933 (Fed. Cir. 2013) (affirming
penalty and noting “the absence of malicious intent does
not make the penalty unreasonable”); Balouris v. U.S.
Postal Serv., No. 2008-3147, 2009 WL 405827, at *2
(Fed. Cir. Feb. 19, 2009) (affirming penalty where
“[r]egardless of his intent, [employee] struck [co-worker]
on a public street”).
     The absence of intent may be relevant to rebut the
government’s assertion of nexus or reasonableness in
some circumstances. In Torres v. Department of Justice,
343 F. App’x 610 (Fed. Cir. 2009), the Board credited a
removed employee’s evidence showing that he did not
know that injections provided by his trainer contained
illegal steroids. Id. at 613. We held that the government
failed to carry its ultimate burden to prove nexus, ex-
plaining “[i]t does not promote the efficiency of the service
for an agency to remove an employee . . . [who] did not
know the substance . . . [he used] was a controlled sub-
stance.” Id. Similarly, in cases in which the Board has
found that an employee inadvertently ingested a con-
trolled substance, it has reversed agency penalties, hold-
ing that “the penalty of removal is unreasonable and that
the maximum reasonable penalty is no penalty at all.”
See, e.g., McNeil v. Dep’t of Justice, 117 M.S.P.R. 533,
539–40 (M.S.P.B. 2012). But, as we have previously
explained, the burden of introducing evidence showing
that, in the circumstances of a particular case, the
HANSEN v. DHS                                           9



charged conduct would not impact the efficiency of the
service or the proposed penalty is unreasonable rests with
the employee. See Schapansky, 735 F.2d at 482; cf. Frey
v. Dep’t of Labor, 359 F.3d 1355, 1360 (Fed. Cir. 2004)
(applying same two-step framework to analysis of removal
for failure to accept reassignment).         Contrary to
Mr. Hansen’s argument, this “requirement for coming
forward with evidence does not shift the overall burden of
proof.” See, e.g., Anderson v. Dep’t of Transp., 827 F.2d
1564, 1576 (Fed. Cir. 1987).
     We read the Board’s opinion as properly applying this
framework in the context of this case. Having found that
the government had introduced sufficient proof to estab-
lish that Mr. Hansen committed the conduct with which
he was charged, the Board considered whether his evi-
dence of inadvertent ingestion rebutted the government’s
assertion of a nexus between the charged conduct and the
efficiency of the service, or otherwise undermined the
reasonableness of the penalty. See J.A. 8–13. The Board
concluded that Mr. Hansen’s evidence of inadvertent use
was weak and, thus, inadequate to undermine the gov-
ernment’s showing of nexus or the reasonableness of the
penalty imposed. We find no arbitrariness, abuse, or
other error in the Board’s conclusion that Mr. Hansen
failed to persuasively rebut the government’s showing of
nexus or its choice of penalty. 2 Mr. Hansen supported his



   2   The Board suggested that Mr. Hansen needed to
prove his theory of inadvertent ingestion by preponderant
evidence. J.A. 13. The quantum of rebuttal evidence
necessary may depend on the quality of the government’s
case—“[i]t may be that little countering evidence would
be required, where, for example, the prima facie case was
minimally supported.” Schapansky, 735 F.2d at 482. We
do not decide in this case precisely how much more evi-
10                                           HANSEN v. DHS




theory of inadvertent ingestion only with “third-hand
hearsay”—his longtime friend’s statement that the barbe-
que host had stated that an unnamed attendee had
brought unmarked marijuana-laced brownies to the
barbeque. J.A. 11. Besides Mr. Hansen, no one testified
that they had even seen the brownies. And though
Mr. Hansen later reported some symptoms consistent
with marijuana ingestion, he did so only after the decid-
ing official explained that she had discredited his version
of events, in part, because she found it “highly questiona-
ble” that he did not report any “behavioral or physiologi-
cal effects” from eating marijuana-laced brownies.
J.A. 20. Further, an expert testified that the symptoms
Mr. Hansen reported were not necessarily caused by
marijuana—inadvertently ingested or otherwise. See
J.A. 12. We therefore affirm the Board’s ruling that on
the entire record, the government bore its burden of
establishing not only that the charged conduct occurred,
but that nexus existed and that the penalty was a reason-
able one. See J.A. 13.
                            II
     We next consider whether the Board erred in finding
that Mr. Hansen was properly ordered to undergo random
drug testing. Drug testing constitutes a search, and the
Fourth Amendment limits an agency’s ability to subject
its employees to drug testing. See Nat’l Treasury Employ-
ees Union v. Von Raab, 489 U.S. 656, 665 (1989). To pass
constitutional muster, testing must be reasonable. See
Holton v. Dep’t of the Navy, 884 F.3d 1142, 1146 (Fed. Cir.
2018). Customs and Border Patrol imposes random drug
testing on employees in “testing designated positions.”


dence Mr. Hansen needed to provide, however, because
the Board correctly found the minimal evidence he ad-
duced insufficient.
HANSEN v. DHS                                          11



Mr. Hansen does not challenge the general reasonable-
ness of this policy. See J.A. 103 (“I am not disputing the
[agency] policy for random drug tests . . . .”). Instead,
Mr. Hansen urges that, absent a specific testing designa-
tion, the agency may not reasonably conduct random drug
tests. He thus asserts that because the government failed
to show that he occupied a testing designated position,
requiring him to undergo a drug test violated his Fourth
Amendment rights.
    We need not decide whether, absent a specific desig-
nation, the agency might permissibly have tested
Mr. Hansen. The Board found that Mr. Hansen occupied
a position subject to random drug testing, and we hold
that substantial evidence supports that fact finding. See
J.A. 6–7. The agency’s “Drug-Free Federal Workplace
Program” handbook lists employees with “access to the
Customs Law Enforcement Automated Systems” as
testing designated, J.A. 32, 34, 58, and evidence offered
by the government indicated that Mr. Hansen’s position
required access to such systems, see J.A. 123–27.
Mr. Hansen attacks this evidence, Pet’r’s Br. 28–33, but
our sole inquiry is whether substantial evidence supports
the Board’s finding. It does, and we do not reweigh evi-
dence.
    For the first time on appeal, Mr. Hansen now also
argues that his test violated his Fourth Amendment
rights because there was “no conceivable basis upon
which [he] could have ascertained that he was subject to
testing.” Pet’r’s Br. 26–27. He asserts “there must be
some objective basis upon which a reasonable employee
would be able to ascertain that he was subject to testing.
Otherwise, testing would be arbitrary and not reasona-
ble.” Pet’r’s Br. 26–27, 33–37. Mr. Hansen previously
argued that the government’s failure to introduce his
notice of testing designation proved that he was not
subject to random drug testing. But before the Board,
despite being represented by counsel, Mr. Hansen did not
12                                           HANSEN v. DHS




allege that any lack of notice rendered his test constitu-
tionally impermissible. Accordingly, we decline to ad-
dress the argument in the first instance. See Solorio v.
United States, 483 U.S. 435, 451 n.18 (1987) (declining to
address Fifth Amendment argument not previously
raised); In re DBC, 545 F.3d 1373, 1380 (Fed. Cir. 2008)
(declining to hear constitutional challenge not raised
before agency); Oral Arg. at 18:03–14, 27:10–15,
http://oralarguments.cafc.uscourts.gov/default.aspx?fl=20
17-2584.mp3. For the same reason, we do not reach
Mr. Hansen’s argument that the agency violated internal
policies requiring written notice prior to testing. See
5 C.F.R. § 1201.56(c)(1) (identifying “harmful error in the
application of the agency’s procedures” as an affirmative
defense); J.A. 110 (“Appellant does not raise any affirma-
tive defenses . . . .”).
                       CONCLUSION
    Having found the parties’ remaining arguments un-
persuasive, we affirm the Board’s decision.
                      AFFIRMED
                          COSTS
     No costs.
