United States Court of Appeals
                            For the Eighth Circuit
                        ___________________________

                                No. 18-1172
                        ___________________________

                            United States of America

                                      Plaintiff - Appellee

                                        v.

                                Willie Earl Clark

                                    Defendant - Appellant

                                 ____________

                     Appeal from United States District Court
                for the Western District of Missouri - Springfield
                                 ____________

                          Submitted: February 13, 2019
                             Filed: June 12, 2019
                                ____________

Before SMITH, Chief Judge, BENTON and STRAS, Circuit Judges.
                              ____________

STRAS, Circuit Judge.

      Willie Clark appeals the order committing him to the custody of the Attorney
General for hospitalization and mental-health treatment. The statute under which
the action was taken, 18 U.S.C. § 4246, authorizes commitment proceedings for
prisoners whose sentences are “about to expire.” Clark argues that the government
did not begin the commitment process until months after his sentence had already
expired, so a necessary condition for his commitment was missing. We agree and
reverse the commitment order.

                                           I.

      Clark was in the custody of the Bureau of Prisons for a long time, first for
possessing a firearm as a felon and later for the first-degree murder of a fellow
inmate. While in prison, he was committed to the custody of the Attorney General
for hospitalization and treatment. United States v. Clark, 655 F. App’x 521 (8th Cir.
2016) (unpublished per curiam); see also 18 U.S.C. § 4245 (authorizing commitment
and hospitalization of “a person serving a sentence of imprisonment,” which cannot
extend past “the expiration of the sentence”).

       The Bureau determined that his prison sentence was due to end in September
2017. But after an audit in July 2016, the Bureau realized it had made a mistake and
had not accounted for the total amount of time that he had spent in custody. Clark’s
true release date, according to the audit, was October 2015. Rather than release
Clark immediately after discovering its error, the government instead filed a petition
asking the district court to continue his commitment.

      The petition relied on 18 U.S.C. § 4246, which authorizes the district court to
commit “a person in the custody of the Bureau of Prisons whose sentence is about
to expire” if he or she has “a mental disease or defect” that creates “a substantial risk
of bodily injury . . . or serious damage to property.” 18 U.S.C. § 4246(a), (d)
(emphasis added). Clark moved to dismiss the petition because his sentence had
already expired. The district court committed Clark anyway.

                                           II.

      The circumstances of this case are unusual, but the lone legal question posed
by the parties is simple: if Clark’s release date had already passed when the

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government petitioned the district court to commit him, was his sentence still “about
to expire”? 

The only conceivable answer is no.

       The adverb “about,” used in this way, refers to something that is on the verge
of happening. See The American Heritage Dictionary of the English Language 5
(5th ed. 2011); Webster’s Third New International Dictionary 5 (2002). And the
verb “to expire,” when referring to a discrete time period like a prison sentence,
means to end. See The American Heritage Dictionary of the English 

; Webster’s Third New International 

; cf.
Black’s Law Dictionary 700 (10th ed. 2014). So a prisoner “whose sentence is about
to expire,” 18 U.S.C. § 4246(a), has one that has not ended yet, but soon will. This
clearly does not describe Clark, whose sentence ended months before the
government filed its petition.

       The government argues, however, that the district court had the authority to
commit Clark because the Bureau had not yet released him from custody when it
filed its petition. It essentially treats the phrase “about to expire” as the same as
“about to be released.” On its own terms, this argument is a stretch, but even if it
were not, the remainder of the statute forecloses it. The statute consistently uses the
word “release” to describe when a prisoner is no longer in custody. See 

(d), (d)(2), (e), (e)(1), (2), (2)(B), (f), (g). The word “expire,” by contrast, appears
just this once. The natural inference is that when the statute means release, it says
so, and when it says “expire,” it must mean something else. See Sosa v. Alvarez-
Machain, 

, 711 n.9 (2004) (describing the presumption that different
words in the same statute mean different things); see also Antonin Scalia & Bryan
A. Garner, Reading Law: The Interpretation of Legal Texts 170 (2012) (“[W]here
[a] document has used one term in one place, and a materially different term in
another, the presumption is that the different term denotes a different idea.”).

     Related statutes confirm this conclusion. See generally Wachovia Bank v.
Schmidt, 

, 315–16 (2006) (explaining that “under the in pari materia

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canon of statutory construction, statutes addressing the same subject matter
generally should be read as if they were one law” (internal quotation marks and
citation omitted)); Scalia & 

. The provision setting out how
federal prison sentences operate, for example, says that “[a] person who has been
sentenced to a term of imprisonment . . . shall be committed to the custody of the
Bureau of Prisons until the expiration of the term imposed, or until earlier released
for satisfactory behavior.” 18 U.S.C. § 3621(a). This provision makes clear that
even though the expectation is that prisoners will be released when their sentences
expire, sometimes it happens earlier, meaning that expiration of a sentence and
release from custody do not necessarily happen at the same time. The same
distinction appears in the provision addressing release, which says that “[a] prisoner
shall be released . . . on the date of the expiration of the prisoner’s term of
imprisonment, less any time credited toward the service of the prisoner’s sentence
[for satisfactory behavior].” 

       The government, doing its best to muddy the water, insists that the phrase
“about to expire” is ambiguous because it is impossible to say exactly when an event
is about to happen. And because it is ambiguous, the government urges us to
interpret section 4246(a) in light of its purpose and conclude that it authorized
Clark’s commitment. See Robinson v. Shell Oil Co., 

, 346 (1997); see
also United States v. S.A., 

, 999 (8th Cir. 1997) (“[Section 4246] is a
mechanism intended to provide a safeguard to the general public and to ensure that
mentally ill and dangerous individuals receive proper treatment.”).

       But ambiguity is context-specific and its presence elsewhere—under some
different set of facts—does not “license” a court to “roam about . . . looking for
[ways] to narrow or expand [the statute] through the process of definition.” Demma
Fruit Co. v. Old Fashioned Enters. (In re Old Fashioned Enters.), 

, 426
(8th Cir. 2001) (citation omitted). If the government had attempted to commit Clark
at some point before his sentence expired—such as one day, one month, or one year
before—then applying the word “about” might have presented an interpretive

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challenge. Here, however, there is no reasonable way to read the phrase “about to
expire” to mean after expiration, no matter how hard we squint at the statute.

       Even if the government is right that policy considerations and the statute’s
purpose favor having Clark committed, the plain language dictates a different result.
Once Clark’s sentence expired without the government having filed its petition, the
district court lacked statutory authority to hold a hearing or commit him. See United
States v. Lapi, 

, 562 (7th Cir. 2006) (holding that the district court
lacked statutory authority for a section 4246 hearing when “the statutory
requirement of certification had not been met” and the defendant was no longer in
federal custody); United States v. Baker, 

, 1324 (6th Cir. 1986) (“[B]y
failing to adhere to the procedures outlined in section 4246, the district court lacked
statutory authority to commit Baker . . . .”). But cf. United States v. Shields, 

, 88–89 (1st Cir. 2011) (holding that the government’s one-day delay in
petitioning for commitment did not require releasing a defendant committed under
18 U.S.C. § 4248). If, as the government suggests, this means that “Congress
enacted into law something different from what it intended,” it is up to Congress,
not us, to fix it. Lamie v. U.S. Tr., 

, 542 (2004).

                                         III.

      We reverse the district court’s judgment.
                      ______________________________




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