UNPUBLISHED ORDER
                         Not to be cited per Circuit Rule 53




           United States Court of Appeals
                              For the Seventh Circuit
                              Chicago, Illinois 60604

                             Submitted July 21, 2005*
                              Decided July 21, 2005

                                       Before

                   Hon. WILLIAM J. BAUER, Circuit Judge

                   Hon. RICHARD D. CUDAHY, Circuit Judge

                   Hon. DIANE S. SYKES, Circuit Judge

No. 05-1209

SCOTT SMITH,                                    Appeal from the United States District
    Petitioner-Appellant,                       Court for the Southern District of
                                                Indiana, Indianapolis Division
      v.
                                                No. 1:04-cv-756-SEB-VSS
              **
MARK BEZY,
    Respondent-Appellee.                        Sarah Evans Barker,
                                                Judge.

                                     ORDER

   Scott Smith was an inmate at the United States Penitentiary in Terre Haute,
Indiana, when he joined a brawl with several other prisoners in the recreation yard.
The prison’s Disciplinary Hearings Officer (DHO) sanctioned Smith with the loss of
27 days’ good conduct time, as well as a period of disciplinary segregation and lost
privileges. Smith exhausted his administrative remedies and then petitioned the


      *
       After an examination of the briefs and the record, we have concluded that oral
argument is unnecessary. Thus, the appeal is submitted on the briefs and the record.
See Fed. R. App. P. 34(a)(2).
      **
          We substitute Mark Bezy, the current warden of the United States
Penitentiary in Terre Haute, for his predecessor, Keith Olson. See FED. R. APP. P.
43(c)(2).
No. 05-1209                                                                    Page 2

district court for a writ of habeas corpus, 28 U.S.C. § 2241, arguing that the DHO
denied him due process during his hearing. Smith has since completed serving his
federal prison time and was released on an Ohio detainer to begin serving a 13-year
state sentence. The district court denied the petition and Smith appeals.

    The respondent first argues that Smith’s appeal is moot because he is no longer
a federal prisoner. When a prisoner is released from incarceration, any challenge to
the validity of his conviction or the length of his sentence becomes moot unless he
continues to suffer collateral consequences that may be redressed in a petition for
habeas corpus. Spencer v. Kemna, 

, 7 (1998). A party asserting that a
claim is moot bears a “heavy burden.” Edwards v. Ill. Bd. of Admissions to the Bar,

, 728 (7th Cir. 2001). The respondent has not met that burden here.
The respondent has not informed us whether Smith remains on federal supervised
release, which is a form of custody, United States v. Trotter, 

, 1152
(7th Cir. 2001), or whether a favorable decision on his petition for habeas corpus
could affect the length of any supervised release term. We also do not know
whether Ohio would credit any of the lost good conduct time against Smith’s state
sentence if he prevails on his § 2241 petition. Thus we cannot be confident that
Smith has nothing to gain from this appeal and, accordingly, proceed to the merits.

   We begin by noting that in addition to challenging his loss of good conduct
credits, Smith also claims that he should not have been placed in segregation or
denied privileges. But a petition for habeas corpus may be used only to challenge
the fact or duration of a prisoner’s confinement. Pischke v. Litscher, 

,
499 (7th Cir. 1999). Disciplinary segregation or a reduction in privileges affects the
nature of the inmate’s custody rather than its duration and, accordingly, may not be
raised in a petition for habeas corpus. Montgomery v. Anderson, 

, 643-
44 (7th Cir. 2001). In contrast, a prisoner may file a petition for habeas corpus to
challenge the loss of good time credits provided that he has a protected liberty
interest in those credits. See Webb v. Anderson, 

, 651-52 (7th Cir.
2000). Here, the respondent does not dispute that Smith has a liberty interest in
his lost credits.

    Smith first argues that the evidence that he was involved in a fight was
insufficient to support the DHO’s decision. Due process requires that the DHO’s
decision to revoke Smith’s good conduct credits be supported by “some evidence” in
the record. Superintendent, Mass. Corr. Inst., Walpole v. Hill, 

, 454
(1985). This is a “lenient standard.” 

. The DHO relied
primarily on a report prepared by Lieutenant Brechbill, who investigated the brawl
and stated that several correctional officers had seen Smith exchanging blows with
another inmate. Further, the report noted that Smith had a cut above his eye, a
swollen lip, and abrasions on his cheek that were consistent with being in a fight.
Lieutenant Brechbill’s report provided adequate support for the DHO’s finding that
Smith participated in the brawl. Although Smith denies his involvement and
claims instead that he sustained his injuries when he lost his grip on a weight-
No. 05-1209                                                                  Page 3

lifting bar while using an exercise machine and the bar struck him in the face, our
task is not to reweigh the evidence that was before the DHO. 

supports the DHO’s finding, and that is all due process requires.

    Smith next argues that the DHO was biased against him. An inmate has a right
to a hearing before an impartial decisionmaker. Wolff v. McDonnell, 

,
570-71 (1974). Although the district court did not specifically address his
contentions, Smith makes two separate allegations of bias. First, he claims that the
facility’s warden told the DHO to find him guilty. This allegation is utterly
unsupported by any evidence in the record and, accordingly, fails. Second, Smith
claims that Lieutenant Brechbill remained in the hearing room after the hearing
and suggests without elaboration that he must have told the DHO to find him
guilty. But the DHO submitted an affidavit stating that Lieutenant Brechbill did
not remain behind. Even if Brechbill was present in the room, this alone did not
deprive Smith of an impartial hearing. See White v. Ind. Parole Bd., 

,
767 (7th Cir. 2001).

                                                                       AFFIRMED.