                   FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

JONAH R.,                                  No. 05-16391
              Petitioner-Appellant,
                v.                           D.C. No.
                                          CV-04-01519-SMM
GILBERT   CARMONA,
                                              OPINION
              Respondent-Appellee.
                                      
      Appeal from the United States District Court
               for the District of Arizona
     Stephen M. McNamee, District Judge, Presiding

                     Argued and Submitted
          January 11, 2006—San Francisco, California

                      Filed May 2, 2006

     Before: John T. Noonan, William A. Fletcher, and
          Consuelo M. Callahan, Circuit Judges.

            Opinion by Judge William A. Fletcher




                            4977
4980                JONAH R. v. CARMONA


                        COUNSEL

Robert J. McWhirter, Federal Public Defender’s Office, Phoe-
nix, Arizona, for the petitioner-appellant.

Linda C. Boone, Thomas C. Simon, Office of the United
States Attorney, Phoenix, Arizona, for the respondent-
appellee.
                    JONAH R. v. CARMONA                  4981
                           OPINION

W. FLETCHER, Circuit Judge:

   Petitioner Jonah R. spent almost 35 months in detention
before he was sentenced to a 30-month term of confinement
under the Federal Juvenile Delinquency Act (“FJDA”), 18
U.S.C. § 5031 et seq. The Federal Bureau of Prisons (“BOP”)
calculates sentences for persons, including juveniles like
Jonah, remanded to its custody. Pursuant to a recently-
adopted policy, the BOP refused to subtract from Jonah’s sen-
tence any of the 35 months he spent in pre-sentence custody.
The district court rejected Jonah’s challenge to this policy.
We hold that juveniles must receive credit for pre-sentence
custody and accordingly reverse.

                      I.   Background

   On June 17, 2001, Jonah was arrested after shooting at a
law enforcement officer while on the Salt River Pima-
Maricopa Indian Reservation. He was charged under 18
U.S.C. § 1153, “Offenses committed within Indian Country,”
with assault with a dangerous weapon in violation of 18
U.S.C. § 113(a)(3), and with discharge of a firearm during a
crime of violence in violation of 18 U.S.C. § 924(c). In Octo-
ber 2001, the district court transferred Jonah, who was 17 at
the time of the incident, to adult status. We reversed in July
2003, holding that because the district court did not obtain
Jonah’s juvenile records as required under FJDA, 18 U.S.C.
§ 5032, it lacked jurisdiction to transfer him for prosecution
as an adult. United States v. Juvenile Male, 336 F.3d 1107,
1110-11 (9th Cir. 2003). After spending nearly 35 months in
custody, mostly while designated as an adult, Jonah was
finally sentenced pursuant to the FJDA on June 7, 2004. He
received 30 months of custody plus another 30 months of
supervised release.

   This appeal concerns the BOP’s refusal to subtract any of
the 35 months of Jonah’s pre-sentence confinement from his
4982                 JONAH R. v. CARMONA
30-month sentence. 18 U.S.C. § 3585(b) provides that “[a]
defendant shall be given credit toward the service of a term
of imprisonment for any time he has spent in official deten-
tion prior to the date the sentence commences . . . .” The
FJDA does not expressly incorporate § 3585. However,
before 1999 the BOP consistently applied § 3585 to juveniles
when calculating their sentences under the FJDA. See Bureau
of Prisons, Sentence Computation Manual (“Old Law”-Pre
CCCA-1984), Program Statement No. 5880.30, at XII-4 (July
16, 1993), available at http://www.bop.gov (declaring that
“[p]resentence time shall be applied to a [juvenile’s] sentence
the same as for an adult . . . .”).

   The BOP reversed course in 1999. A year earlier, a U.S.
Virgin Islands district court, noting that “the whole purpose
of treating minors as juveniles [is] to take them out of the
criminal process[,]” concluded that a juvenile is not a “defen-
dant” who serves a “sentence” for a federal crime within the
meaning of § 3585. United States v. D.H., 12 F. Supp. 2d 472,
474 (D.V.I. 1998). The court held that the BOP lacked the
statutory authority to apply § 3585 to juveniles. Id. at 475.
The BOP revised its policy to accord with D.H. It now refuses
to credit juveniles with pre-sentence time served. See Bureau
of Prisons, Operations Memorandum No. 007-2003 (5880), at
1 (Feb. 19, 2003).

   Jonah filed a habeas petition pursuant to 28 U.S.C. § 2241
to challenge the BOP’s current policy. Rejecting a magis-
trate’s report and recommendation, the district court decided
to follow D.H. It reasoned that § 3585(b) applies only to “a
defendant who has committed an offense and has received a
sentence of imprisonment.” According to the district court,
juveniles commit “acts of juvenile delinquency,” not offenses,
and they “receive a term of official detention,” not imprison-
ment. Hence § 3585(b) by its plain terms does not intersect
with the FJDA, and the BOP “cannot grant juveniles credit for
pretrial custody . . . .” This appeal followed.
                       JONAH R. v. CARMONA                    4983
                         II.   Discussion

   [1] We review de novo the denial of a habeas petition filed
pursuant to 28 U.S.C. § 2241. Taylor v. Sawyer, 284 F.3d
1143, 1147 (9th Cir. 2002). Whether a juvenile whose status
is adjudicated under the FJDA must receive credit against his
or her sentence for time spent in pre-sentence custody is a
question of first impression. We begin with a close look at the
relevant statutes.

                  A.    Statutory Background

   The first statute governs the calculation of sentences for
adult offenders. Congress first enacted what eventually
became § 3585 in 1932. This statute, which was codified in
part at 18 U.S.C. § 3568, provided that a convicted defen-
dant’s sentence “shall commence to run from the date on
which such person is received at the penitentiary, reformatory,
or jail for service of said sentence . . . .” Act of June 29, 1932,
Pub. L. No. 72-210, 47 Stat. 381, 381. Although the statute
did not explicitly instruct the BOP to credit convicted defen-
dants with time spent in pre-sentence custody, federal courts,
as a “general practice,” “provide[d] defendants credit against
their sentence for time spent in jail for lack of bail.” Stapf v.
United States, 367 F.2d 326, 328 (D.C. Cir. 1966).

   There was a judicially-created exception to this “general
practice.” For crimes that carried mandatory minimum sen-
tences, courts believed that they lacked the statutory power to
afford defendants pre-sentence credit. Stapf, 367 F.2d at 328.
In 1960, Congress, both signaling its approval of the “general
practice” and indicating an intention to make § 3568 more
universally applicable, amended the statute to eliminate this
exception. Section 3568 as amended provided that

    the Attorney General shall give any [person con-
    victed of an offense in a court of the United States]
    credit toward service of his sentence for any days
4984                 JONAH R. v. CARMONA
    spent in custody prior to the imposition of sentence
    by the sentencing court for want of bail set for the
    offense under which sentence was imposed where
    the statute requires the imposition of a minimum
    mandatory sentence.

Act of Sept. 2, 1960, Pub. L. No. 86-691, 74 Stat. 738, 738.

   As the D.C. Circuit noted, Congress did not expressly make
the amended § 3568 applicable outside the mandatory mini-
mum context “because it assumed that a credit for presentence
custody for want of bail would continue to be provided by
sentencing courts as a matter of course.” Stapf, 367 F.2d at
328. However, some courts misunderstood the amendment
and held that credit was required under § 3568 only for those
defendants whose convictions carried mandatory minimum
sentences. See Sobell v. United States, 407 F.2d 180, 181 (2d
Cir. 1969); Bryans v. Blackwell, 387 F.2d 764, 766 (5th Cir.
1967). In part to correct this misunderstanding, Congress
again amended § 3568 in 1966 to provide that “any person
convicted of an offense” shall receive “credit toward service
of his sentence for any days spent in custody in connection
with the offense or acts for which sentence was imposed[,]”
regardless of whether the sentence involved a statutory mini-
mum. Bail Reform Act of 1966, Pub. L. No. 89-465, § 4, 80
Stat. 214, 217. We observed shortly thereafter that, “[a]s
amended, Section 3568 . . . require[s] that the Attorney Gen-
eral give credit in all cases of presentence custody.” Williams
v. United States, 440 F.2d 684, 685 (9th Cir. 1971) (emphasis
added).

   The final relevant change came eighteen years later when
Congress passed the Sentencing Reform Act of 1984. The
statute repealed § 3568, see Pub. L. No. 98-473, § 212, 98
Stat. 1987, 1987 (1984), and replaced it with 18 U.S.C.
§ 3585. See id. ch. 227, 98 Stat. 2001 (codified at 18 U.S.C.
§ 3585); see also United States v. Wilson, 503 U.S. 329, 334-
                     JONAH R. v. CARMONA                       4985
37 (1992) (discussing replacement of § 3568 with § 3585).
Section 3585 provides, in relevant part:

    A defendant shall be given credit toward the service
    of a term of imprisonment for any time he has spent
    in official detention prior to the date the sentence
    commences —

       (1) as a result of the offense for which the sen-
    tence was imposed; or

       (2) as a result of any other charge for which the
    defendant was arrested after the commission of the
    offense for which the sentence was imposed . . . .

18 U.S.C. § 3585(b). Section 3585 substitutes “official deten-
tion” for “custody,” and it enlarges the class of persons who
receive pre-sentence credit, but is otherwise quite similar to
§ 3568. See, e.g., Wilson, 503 U.S. at 334 (holding that “the
Attorney General must continue to compute the credit under
§ 3585(b) as he did under the former § 3568”).

   The second statute governs the treatment of juveniles. The
Federal Juvenile Delinquency Act (“FJDA”) was first passed
in 1938 to remedy “the unsatisfactory existing law” that
required “juveniles to be treated and prosecuted in the same
manner as adults.” S. Rep. No. 75-1989, at 1 (1938). The stat-
ute furthers rehabilitative goals by “removing juveniles from
the ordinary criminal justice system and by providing a sepa-
rate system of ‘treatment’ for them.” United States v.
Frasquillo-Zomosa, 626 F.2d 99, 101 (9th Cir. 1980). As
originally enacted, the FJDA provided, in pertinent part:

    In the event that the court finds [a] juvenile guilty of
    juvenile delinquency . . . it may commit the delin-
    quent to the custody of the Attorney General for a
    period not exceeding his minority, but in no event
    exceeding the term for which the juvenile could have
4986                JONAH R. v. CARMONA
    been sentenced if he had been tried and convicted of
    the offense which he had committed.

Act of June 16, 1938, Pub. L. No. 75-666, 52 Stat. 764, 765.

  Congress revised the FJDA in 1974 in the Juvenile Justice
and Delinquency Prevention Act (“JJDPA”), Pub. L. No. 93-
415, 88 Stat. 1109 (1974). The JJDPA amended the provision
governing juvenile sentencing to state:

    [C]ommitment . . . shall not extend beyond the juve-
    nile’s twenty-first birthday or the maximum term
    which could have been imposed on an adult con-
    victed of the same offense, whichever is sooner,
    unless the juvenile has attained his nineteenth birth-
    day at the time of disposition, in which case . . .
    commitment . . . shall not exceed the lesser of two
    years or the maximum term which could have been
    imposed on an adult convicted of the same offense.

Id. § 507, 88 Stat. 1136 (codified as amended at 18 U.S.C.
§ 5037(b)). This provision was substantially revised in 1984,
when Congress redrafted it to read as follows:

    The term for which official detention may be ordered
    for a juvenile found to be a juvenile delinquent may
    not extend —

       (1) in the case of a juvenile who is less than
    eighteen years old, beyond the lesser of —

        (A) the date when the juvenile becomes
    twenty-one years old; or

         (B) the maximum term of imprisonment that
    would be authorized by section 3581(b) if the juve-
    nile had been tried and convicted as an adult; or
                         JONAH R. v. CARMONA                       4987
         (2) in the case of a juvenile who is between
      eighteen and twenty-one years old —

           (A) who if convicted as an adult would be
      convicted of a Class A, B, or C felony, beyond five
      years; or

           (B)      in any other case beyond the lesser of —

              (i)    three years; or

             (ii) the maximum term of imprisonment
      that would be authorized by section 3581(b) if the
      juvenile had been tried and convicted as an adult.

Sentencing Reform Act of 1984, Pub. L. No. 98-473, § 214,
98 Stat. 1987, 2013 (1984) (codified at 18 U.S.C. § 5037(c)).

   Finally, the Youth Corrections Act (“YCA”) was passed in
1950 “to make available for the discretionary use of the Fed-
eral judges a system for the sentencing and treatment of per-
sons under the age of 22 years who have been convicted of
crime . . . that will promote the rehabilitation of those who . . .
show promise of becoming useful citizens . . . .” H.R. Rep.
No. 81-2979 (1950), reprinted in 1950 U.S.C.C.S. 3983,
3983. The YCA shared the FJDA’s emphasis on rehabilita-
tion. Compare Dorszynski v. United States, 418 U.S. 424, 433
(1974) (observing that the YCA “focused primarily on correc-
tion and rehabilitation”), with United States v. Juvenile, 347
F.3d 778, 785 (9th Cir. 2003) (discussing the FJDA’s rehabili-
tative purpose). If a court determined that a person under age
22 should be classified as a “youth offender,” the YCA autho-
rized the court, “in lieu of the penalty of imprisonment other-
wise provided by law, [to] sentence the youth offender to the
custody of the Attorney General for treatment and supervision
. . . .” Act of Sept. 30, 1950, Pub. L. No. 81-865, § 5010,
reprinted in 1950 U.S.C.C.S. 1079, 1080.1 The Sentencing
  1
   The FJDA and the YCA addressed different populations. The FJDA
applies to individuals under age 18, while the YCA applied to individuals
4988                  JONAH R. v. CARMONA
Reform Act of 1984, which also revised the FJDA, repealed
the YCA. See Pub. L. No. 98-473, § 218(a), 98 Stat. 1987,
2027 (1984).

                       B.   Interpretation

   [2] With this backdrop in mind, we must decide whether
Congress intended § 3585 to apply to juveniles. As always,
we begin with the statute’s plain meaning. Botosan v. Paul
McNally Realty, 216 F.3d 827, 831 (9th Cir. 2000). If the stat-
ute’s terms are ambiguous, we may use canons of construc-
tion, legislative history, and the statute’s overall purpose to
illuminate Congress’s intent. See Milne v. Stephen Slesinger,
Inc., 430 F.3d 1036, 1045 (9th Cir. 2005).

   Ordinarily we would give substantial deference to the
BOP’s interpretation of § 3585 and the FJDA. See Pacheco-
Camacho v. Hood, 272 F.3d 1266, 1268 (9th Cir. 2001). We
do not do so here for several reasons. First, the government
did not argue for any such deference in its brief. Second, the
BOP’s current interpretation of the statutes at issue contra-
dicts its previous interpretation. See Norfolk So. Ry. Co. v.
Shanklin, 529 U.S. 344, 356 (2000) (affording no deference
to an agency’s interpretation when it “contradicts the agency’s
own previous construction”). Finally, by its own admission,
the BOP changed its interpretation because of a judicial deci-
sion, not because its particular expertise led it to do so.

                      1.    Plain Meaning

  The D.H. court held that the plain meaning of § 3585 ren-
ders it inapplicable to juveniles:

between the ages of 18 and 22. See William S. Sessions & Faye M.
Bracey, A Synopsis of the Federal Juvenile Delinquency Act, 14 St.
Mary’s L.J. 509, 517 (1983).
                     JONAH R. v. CARMONA                    4989
    D.H. categorically is not a “defendant.” D.H. is an
    adjudicated juvenile delinquent. While he is in offi-
    cial detention, he is not serving a “sentence” for a
    federal crime . . . .

    . . . . Section 3585 applies to “defendant” serving a
    sentence imposed for the “commission of an
    offense.” “Offense” is not an act of “juvenile delin-
    quency” . . . . D.H. was committed to official deten-
    tion under section 5037 as a juvenile whom the
    Court found to have committed acts of juvenile
    delinquency. Since he is not in official detention
    under a sentence after being found guilty of a crimi-
    nal offense, section 3585 does not apply and he is
    not entitled to presentence credit.

12 F. Supp. 2d at 474. The district court in Jonah’s case
agreed with D.H., concluding that a juvenile is not a “defen-
dant” “sentenced” for an “offense,” and thus cannot fit within
the terms of § 3585.

   [3] “[P]lain meaning, like beauty, is sometimes in the eye
of the beholder.” Florida Power & Light Co. v. Lorion, 470
U.S. 729, 737 (1985). We disagree with the district courts in
this case and in D.H. about the plain meaning of § 3585.
Because “[a] successful prosecution under” the FJDA “results
in a civil adjudication of status, not a criminal conviction[,]”
United States v. Doe, 53 F.3d 1081, 1083 (9th Cir. 1995), a
somewhat different vocabulary is sometimes used in the juve-
nile justice system. However, most of the terms that are so
purportedly foreign to the FJDA — “defendant,” “offense,”
and “sentence” — are frequently used in connection with
juveniles. The FJDA distinguishes between “juvenile delin-
quency” and “crime” when it defines the terms, see 18 U.S.C.
§ 5031, but it also conflates the two. For example, the FJDA
provides for federal jurisdiction over “a juvenile alleged to
have committed an act of juvenile delinquency” if the Attor-
ney General certifies that “the offense charged is a crime of
4990                 JONAH R. v. CARMONA
violence . . . .” 18 U.S.C. § 5032 (emphasis added). Another
statute in Title 18 expressly defines “offender” as including a
person “adjudged to have committed an act of juvenile delin-
quency.” 18 U.S.C. § 4101(e).

   [4] We also routinely refer to juveniles as “defendants” and
to a juvenile’s term of detention as a “sentence.” See, e.g.,
United States v. Leon H., 365 F.3d 750, 752-53 (9th Cir.
2004); Juvenile, 347 F.3d at 787. In this very case the district
court referred to Jonah’s other acts of juvenile delinquency as
“ ‘offense[s].’ ” Juvenile Male, 336 F.3d at 1109 (quoting the
district court’s decision regarding transfer to adult status).
Even the BOP refers to juveniles with vocabulary that,
according to the D.H. court, should be reserved for adult
offenders. See Bureau of Prisons, Juvenile Delinquents, Pro-
gram Statement No. 5216.05, at 1 (Sept. 1, 1999) (stating that
juveniles are “sentenced” under the FJDA); id. at 2 (defining
“juvenile” in part as someone under 18 who is “convicted” of
a federal violation).

   The district court’s understanding of the plain meaning of
§ 3585 rests in large measure on our decision in United States
v. Doe, 53 F.3d 1081 (9th Cir. 1995). In Doe, we addressed
whether 18 U.S.C. § 3583(a), which authorizes a term of
supervised release to follow “a term of imprisonment for a
felony or a misdemeanor,” applies to juveniles. Because juve-
niles receive civil adjudications of status, not convictions for
felonies or misdemeanors, we held that § 3583(a) does not
authorize supervised release for juveniles. Id. at 1083-84. Doe
has limited instructive force. The distinction we had previ-
ously drawn between “misdemeanor” and “felony,” on one
hand, and “act of juvenile delinquency,” on the other, ren-
dered Doe’s terms more unsuitable for use in the juvenile con-
text than those at issue here. See United States v. Gonzalez-
Cervantes, 668 F.2d 1073, 1076 (9th Cir. 1981). Moreover,
Congress’s subsequent adoption of legislation authorizing
supervised release for juveniles, see 21st Century Dep’t of
Justice Appropriations Authorization Act, Pub. L. No. 107-23,
                     JONAH R. v. CARMONA                    4991
116 Stat. 1758, 1896-97 (2002), cautions against a too-literal
reading of Title 18 as applied to juveniles.

   [5] Finally, we note that § 3568, the predecessor of § 3585,
contained a single express exception: its pre-sentence custody
credit did not apply to “offense[s] triable by court-martial,
military commission, provost court, or other military tribu-
nal[.]” See Bail Reform Act of 1966, Pub. L. No. 89-466, § 4,
80 Stat. 214, 217; United States v. Allen, 17 M.J. 126, 127
(C.M.A. 1984). When Congress replaced § 3568 with § 3585,
it eliminated this express exception. The canon expressio
unius est exclusio alterius supports the conclusion that Con-
gress intended § 3568 to apply to all other categories of per-
sons in federal custody, including juveniles, and that Congress
knows how to craft an exception when it intends one. Section
3585’s elimination of § 3568’s only express exception sug-
gests that the statute should have wider, not narrower, appli-
cability.

  [6] We therefore conclude that the terms of § 3585 do not
unambiguously preclude its application to juveniles. We turn
to other canons of construction to determine whether Con-
gress intends juveniles to benefit from its terms.

                      2.   Related Statute

   [7] It is a “rudimentary principle[ ] of construction” that
“statutes dealing with similar subjects should be interpreted
harmoniously.” Jett v. Dallas Indep. Sch. Dist., 491 U.S. 701,
738-39 (1989) (Scalia, J., concurring). In 1977, Congress
enacted a statute to regulate the transfer of prisoners in and
out of the United States. Act of Oct. 28, 1977, Pub. L. No. 95-
144, 91 Stat. 1215 (codified at 18 U.S.C. § 4100 et seq.). Part
of the transfer statute concerns the calculation of sentences for
prisoners transferred to the United States. See 18 U.S.C.
§ 4105.

   [8] The transfer statute provides that “[t]he transferred
offender shall be given credit toward service of the sentence
4992                 JONAH R. v. CARMONA
for any days, prior to the date of commencement of the sen-
tence, spent in custody in connection with the offense or acts
for which the sentence was imposed.” 18 U.S.C. § 4105(b)
(emphasis added). An “offender” is defined as “a person who
has been convicted of an offense or who has been adjudged
to have committed an act of juvenile delinquency.” Id.
§ 4101(e) (emphasis added). Put differently, an American
juvenile arrested elsewhere receives credit for pre-sentence
custody served abroad when he or she is transferred to an
American detention facility.

   [9] The House Report on the transfer statute declares that
its pre-sentence credit provision “parallels section 3568 of
Title 18 . . . .” H.R. Rep. 95-720, at 34 (1977), reprinted in
1977 U.S.C.C.A.N. 3146, 3157. In the past we have required
that the transfer statute and the general pre-sentence custody
provision of Title 18 be interpreted similarly in order to avoid
inconsistent treatment of similar categories of prisoners. Ajala
v. U.S. Parole Comm’n, 997 F.2d 651, 655 (9th Cir. 1993).
The transfer statute points to the obvious conclusion that
§ 3585 should apply to the FJDA to ensure that juveniles
arrested here receive the same treatment as juveniles arrested
abroad.

   The government asks us to take a different lesson from the
transfer statute, arguing that it demonstrates that Congress
speaks clearly and expressly when it wants juveniles to
receive pre-sentence credit. It strains credulity, however, to
think that Congress would intend to deal more harshly with
juveniles unlucky enough to be arrested in the United States.
Moreover, disparate treatment of the sort the government
urges us to countenance might well trigger equal protection
concerns. Cf. Myers v. United States, 446 F.2d 232, 234 (D.C.
Cir. 1971) (holding that the Fifth Amendment requires that all
similarly-situated prisoners receive credit under § 3568);
Stapf, 367 F.2d at 329 (“Denial of credit . . . where others
guilty of crimes of the same or greater magnitude automati-
cally receive credit, would entail an arbitrary discrimination
                     JONAH R. v. CARMONA                  4993
within the power and hence the duty of the court to avoid.”).
We must interpret statutes to avoid such constitutional diffi-
culties whenever possible. See INS v. St. Cyr, 533 U.S. 289,
299-300 (2001).

                   3.   Legislative History

   [10] To suggest that Congress intentionally singled out
juveniles arrested abroad for special treatment ignores the
general practice in place in 1977, when it enacted the transfer
statute. At that time, both the BOP and federal courts under-
stood that § 3568, the predecessor of § 3585, applied to juve-
niles. In 1984, when the pre-sentence custody and juvenile
justice provisions of Title 18 underwent extensive revision,
this general practice went unmentioned. This history strongly
suggests that when Congress drafted the transfer statute, it
expected that juveniles would receive credit for pre-sentence
custody as a matter of course.

   Starting in 1969, the BOP, as part of its implementation of
the 1966 Bail Reform Act, announced that it would give juve-
niles credit against their sentences for time spent in pre-
sentence custody. See Proceedings of Seminar for Newly
Appointed United States District Judges, 75 F.R.D. 89 (1976)
(discussing BOP Policy Statement No. 7600.51 (Oct. 30,
1969)). This practice was followed in 1984. See Bureau of
Prisons, Sentence Computation Manual (“Old Law”-Pre
CCCA-1984), Program Statement 5880.30, at VI-2 (June 30,
1997). And, according to its Sentencing Manual then in effect,
courts agreed with the practice. Id. (“Case law confirmed the
applicability of [§ 3568] to . . . the Federal Juvenile Delin-
quency Act . . . .”). Moreover, the practice was generally in
harmony with Congress’s consistent efforts to expand the
applicability of § 3568 in the 1960s.

   Analogously, most federal courts during that period
required the BOP to give pre-sentence credit to youthful
offenders sentenced under the now-defunct YCA, a statute
4994                 JONAH R. v. CARMONA
that shared the FJDA’s goals and purposes. See United States
v. Hamilton, 300 F. Supp. 728, 730 (E.D.N.C. 1969); EK v.
United States, 308 F. Supp. 1155, 1156-57 (S.D.N.Y. 1969);
United States v. Thomas, 300 F. Supp. 1201, 1203 (S.D.N.Y.
1969). Indeed, at least twice courts rejected a variant of the
argument the government makes here — that, because § 3568
by its terms applied only to those subjected to “imprison-
ment,” and because offenders received “treatment and super-
vision” under the YCA, § 3568 did not apply to their
sentences. Thomas, 300 F. Supp. at 1203; EK, 308 F. Supp.
at 1156-57. Although one court disagreed, see Viggiano v.
United States, 274 F. Supp. 985, 986 (S.D.N.Y. 1967), the
BOP ultimately adopted the position of the Thomas and EK
courts as its own. See United States v. Robinson, 720 F.2d
203, 207 n.3 (D.C. Cir. 1983) (describing BOP’s sentencing
practices for the YCA).

   The D.H. court insisted that the YCA “has been repealed,
and there is no basis to extend interpretations of that act to”
the FJDA. 12 F. Supp. 2d at 473 n.1. However, the BOP,
interpreting the law in effect before 1984, lumped the two
statutes together when it declared that juveniles were to get
pre-sentence credit. BOP, Sentence Computation Manual
(“Old Law”-Pre CCCA-1984), at VI-2 (June 30, 1997). Also,
the YCA, which shared the FJDA’s rehabilitative goals, was
repealed in part because, “contrary to the intent of Congress,
the [YCA’s] special sentencing provisions [had] often served
to place youthful persons in a disadvantageous position” vis-
à-vis adults. H.R. Conf. Rep. No. 98-1017, at 57 (1984); see
also Carter v. United States, 306 F.2d 283, 285 (D.C. Cir.
1962) (justifying a longer sentence under the YCA because
“rehabilitation [under the YCA] may be regarded as compris-
ing the quid pro quo for a longer confinement but under dif-
ferent conditions and terms than a defendant would undergo
in an ordinary prison”). It would be odd indeed to interpret the
YCA’s repeal as evidence that Congress wanted to treat adults
more favorably than “youthful persons.”
                     JONAH R. v. CARMONA                    4995
   [11] There are other suggestions that Congress in 1984
intended juveniles to continue to receive credit for pre-
sentence custody. None of the Congressional reports on the
1984 Act give any indication whether § 3585 is supposed to
apply to the FJDA. See H.R. Conf. Rep. No. 98-1017, at 54
(1984) (explaining repeal of § 3568); S. Rep. No. 98-225, at
129 (1984) (explaining enactment of § 3585); id. at 155
(explaining revision of FJDA § 5037). This legislative silence
in the face of a generally-accepted practice is evidence that
Congress wanted to leave the existing understanding in place.
See Castro-Cortez v. INS, 239 F.3d 1037, 1052 (9th Cir.
2001) (stating that “congressional silence is instructive” when
Congress enacts a law after courts had developed a standard
practice). Moreover, the Senate Report on the 1984 Act pro-
vides that § 5037(c), the provision under which Jonah was
sentenced, “parallels the 1974 [JJDPA] provision set forth in
current law for juveniles under 18 at the time of the proceed-
ing.” S. Rep. No. 98-225, at 155 (1984). According to the
Senate Report on the JJDPA, the 1974 statute amended
§ 5037 “to provide that a juvenile is entitled to all rights that
would be accorded an adult in a criminal prosecution . . . .”
S. Rep. No. 93-1011, reprinted in 1974 U.S.C.C.A.N. 5283,
5321 (emphasis added).

   The government nonetheless contends that subsequent leg-
islative action, namely a 1986 amendment to § 5037 dealing
with good time credit, confirms Congress’s intent to put juve-
niles beyond the reach of § 3585. Under 18 U.S.C. § 3624(b),
offenders may receive “good time” credit to shorten their sen-
tences. The 1986 amendment revised § 5037 to read in part,
“Section 3624 is applicable to an order placing a juvenile
under detention.” 18 U.S.C. § 5037(c) (amended 1986). If
courts could incorporate provisions of the sections of Title 18
applicable to adults into the FJDA without explicit Congres-
sional instruction, the government reasons, the 1986 amend-
ment will have been superfluous; by its existence, Congress
has signaled that courts should refuse to extend § 3585 or the
FJDA unless Congress expressly tells them to do so.
4996                 JONAH R. v. CARMONA
   [12] The government’s attempt to distill Congress’s intent
from the 1986 amendment conflicts with the stated intentions
of its sponsors. Senator Thurmond explained when he intro-
duced the bill to amend § 5037, “During the 7 months follow-
ing [the] enactment [of the 1984 sentencing law], its
operation in practice has exposed the need for some technical
amendments and other minor adjustments.” 131 Cong. Rec.
S7399 (daily ed. June 4, 1985) (Statement of Sen. Thurmond)
(emphasis added). The record continues:

    The [FJDA] does not now clearly provide that the
    “good time” provisions applicable to adults are also
    applicable to juveniles. If terms of incarceration for
    juveniles are to be made fully determinate . . . there
    is little justification for making juvenile sentences
    more severe than adult sentences. This amendment
    carries forward the current practice of granting
    “good time” to juveniles.

131 Cong. Rec. at S7399 (emphasis added). Far from an
instruction from Congress to courts not to venture any further
than the FJDA’s terms expressly provide, the 1986 amend-
ment reflects Congress’s desire to make sure that existing sen-
tencing practices maintaining parity between the treatment of
adults and juveniles continue. That Congress saw no need to
rewrite § 5037 also to include a reference to § 3585 indicates
that Congress saw no problem with the FJDA’s “operation in
practice.” That is, it indicates that Congress was satisfied with
the BOP’s understanding that juveniles received credit for
time spent in pre-sentence custody.

                    4.   Statutory Purpose

   [13] The purposes of the statutes at issue confirm that juve-
niles should be included in, and should benefit from, § 3585.
The FJDA creates a separate system of criminal justice for
juveniles to “shield[ ]” them from the ordinary criminal jus-
tice system and to provide them with “protective treatment
                     JONAH R. v. CARMONA                    4997
not available to adults accused of the same crimes.” Doe, 53
F.3d at 1083; see also Frasquillo-Zomosa, 626 F.2d at 101
(noting that this is the FJDA’s “purpose”). The primary goal
of the FJDA is rehabilitative, not punitive; we have thus
declared that “a least-restrictive standard for confinement” is
“implicit in the structure and purposes of the FJDA sentenc-
ing provisions.” Juvenile, 347 F.3d at 785. This emphasis on
rehabilitation and leniency makes it highly unlikely that Con-
gress meant to treat juveniles more harshly than adult offend-
ers.

   [14] Section 3585 rests on a foundation of basic fairness.
“[I]f a person is detained in a pretrial setting, while enjoying
the presumption of innocence, it is only fair that the govern-
ment give him credit for that time at the end of his sentence.”
United States v. Wickman, 955 F.2d 592, 595 (8th Cir. 1992)
(Lay, J., dissenting); see also Campbell v. McGruder, 580
F.2d 521, 530 (D.C. Cir. 1978) (observing that § 3568 reflects
that “it is difficult to distinguish pretrial incarceration from
punishment”). A juvenile’s entitlement to a presumption of
innocence is no weaker than an adult’s, and no magic happens
simply because juveniles lose their liberty after a civil adjudi-
cation, rather than a successful prosecution. The fact remains
that Jonah is (and was) in detention, and no amount of seman-
tics — “rehabilitation” versus “punishment,” “adjudication”
versus “prosecution,” “defendant” versus “juvenile delin-
quent” — can make it otherwise. See In re Gault, 387 U.S. 1,
29-30 (1967) (“So wide a gulf between the . . . treatment of
the adult and of the child requires a bridge sturdier than mere
verbiage . . . .”).

   The BOP’s treatment of juveniles whose status is adjudi-
cated in the District of Columbia illustrates the arbitrariness
of its refusal to give Jonah pre-sentence credit for time
already spent in incarceration. D.C. Code § 24-431(a), which
is based on § 3568, provides that “[e]very person shall be
given credit . . . for time spent in custody . . . as a result of
the offense for which the sentence was imposed.” The BOP,
4998                  JONAH R. v. CARMONA
which computes sentences for D.C. inmates in addition to its
federal duties, applies this “jail time credit” against juveniles’
sentences just as it does for adults. See Bureau of Prisons,
D.C. Sentence Computation Manual, Program Statement No.
5880.32, at XIV-6 (Jan. 23, 2001). Admittedly, the District’s
equivalent to the FJDA does not use a different vocabulary to
discuss sentencing options for “youth offenders.” See D.C.
Code § 24-803(2). This difference in terminology cannot jus-
tify a difference in treatment. If a 15 year-old spends 100 days
in pre-sentence custody in a city jail, the BOP gives him
credit. If his 100 days are served across the street for a federal
violation, the BOP does not, despite the fact that the individu-
al’s rehabilitative needs and society’s interest in punishment
do not differ in the two cases.

   When asked to do so at oral argument, the government
declined to give a policy rationale for treating juveniles more
harshly than adults. Its reluctance is understandable. We can
think of no sensible reason why Jonah’s liberty, which he lost
for almost three years before his culpability was adjudicated,
is worth less than a similarly-situated adult’s.

                          Conclusion

   [15] We conclude that, when Congress revised § 3585 and
the FJDA in 1984, it intended for the BOP to continue to
credit juveniles with time spent in pre-sentence custody.
Jonah has now been incarcerated for 58 months based on a
sentence of 30 months. The district court’s decision is
reversed, and Jonah’s petition for a writ of habeas corpus is
granted. Our decision does not affect Jonah’s period of super-
vised release.

  REVERSED.
