                    FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

GARY SIMPSON,                                   No. 07-16228
                Plaintiff-Appellant,               D.C. No.
                v.                            CV-03-00591-MCE/
Sergeant JEFFREY THOMAS,                             GGH
               Defendant-Appellee.
                                                  OPINION

        Appeal from the United States District Court
            for the Eastern District of California
        Morrison C. England, District Judge, Presiding

                    Argued and Submitted
          April 16, 2008—San Francisco, California

                       Filed June 11, 2008

      Before: Stephen S. Trott and Sidney R. Thomas,
   Circuit Judges, and Michael R. Hogan,* District Judge.

                     Opinion by Judge Trott




  *The Honorable Michael R. Hogan, United States District Judge for the
District of Oregon, sitting by designation.

                                6635
6638                 SIMPSON v. THOMAS


                        COUNSEL

Carter C. White, Supervising Attorney, and Anjuli Fiedler and
Rachel Golick, Certified Law Students, U.C. Davis School of
Law, Davis, California, for the plaintiff/appellant.

Misha D. Igra, Deputy Attorney General, Sacramento, Cali-
fornia, for the defendant/appellee.
                      SIMPSON v. THOMAS                    6639
                          OPINION

TROTT, Circuit Judge:

   Gary Simpson filed suit under 42 U.S.C. § 1983 alleging
that Sergeant Jeffrey Thomas, a corrections officer at the Cali-
fornia Medical Facility (“CMF”) state prison in Vacaville,
California, used excessive force after Simpson did not comply
with Thomas’s orders. For impeachment purposes, the district
court admitted evidence of Simpson’s three prior convictions
more than ten years old pursuant to Federal Rule of Evidence
609(b), explaining that because his prior convictions were uti-
lized pursuant to California’s Three Strikes Law to enhance
his current sentence, “those prior strikes were not and do not
wash out under state law.” Additionally, pursuant to Heck v.
Humphrey, 512 U.S. 477 (1994), the district court excluded
any evidence or testimony that Simpson acted in self-defense
after Thomas allegedly punched him, explaining that such
evidence would invalidate the finding of guilt in Simpson’s
prison disciplinary proceeding.

  After a jury trial resulted in a verdict in Thomas’s favor,
Simpson filed a motion for a new trial, which the district court
denied. Simpson v. Thomas, No. 2:03-CV-00591, 2007 WL
1687092 (E.D.C.A. June 8, 2007).

   We have jurisdiction pursuant to 18 U.S.C. § 1291, and we
reverse and remand for a new trial. We hold that the use of
prior convictions older than ten years to enhance a sentence
for a separate conviction pursuant to California’s Three
Strikes Law does not bring those prior convictions within the
ten year time limit of Federal Rule of Evidence 609. Addi-
tionally, we hold that Heck does not create a rule of evidence
exclusion and therefore may not be used to bar relevant evi-
dence.
6640                 SIMPSON v. THOMAS
                              I

                     BACKGROUND

A.     Factual Background

   In May of 2000, Simpson pled nolo contendere to second
degree armed robbery. He was sentenced to 216 months in
state prison. The sentence included 60 months for the armed
robbery plus a 156 month enhancement for his prior felonies.

   This case arises out of an altercation on March 22, 2002,
between Simpson and Thomas while Simpson was a prisoner
at CMF. Both parties agree that Simpson refused to immedi-
ately comply with Thomas’s order to remove a sheet from his
cell window. After Simpson refused to remove the sheet,
Officer Michael Webb unlocked the cell door, and Thomas
entered the cell. The parties dispute what happened next.

  1.    Simpson’s Testimony

   Simpson testified that he got down off his bunk when
Thomas asked him to, but refused to “turn around and cuff
up.” Simpson said that Thomas called him a profane name,
took out his pepper spray, and threatened to use the spray.
Simpson turned around and told Thomas he did not need to
use the pepper spray. As Simpson turned around, “a struggle
ensued” and Webb pepper sprayed both Simpson and
Thomas. Eventually, Simpson “had [Thomas] by the neck . . .
and took him down to [Simpson’s cellmate’s] bunk.” During
the struggle, Simpson grabbed Thomas’s pepper spray and
“somehow it got on the floor.” After Simpson’s cellmate told
Simpson to let Thomas up, Simpson told Thomas, “I’m going
to let you go, and I’m going to get up and put my hands
behind my back.”

  When Simpson released Thomas, Thomas grabbed Simp-
son’s hands and “roughed me out of the cell.” Once out of the
                        SIMPSON v. THOMAS                6641
cell, Simpson was getting to the ground when Thomas
slammed him down. After he was on the ground, Simpson
said Thomas “punched me a few times on the right side of my
face.”

  2.    Thomas’s Testimony

   Thomas testified that he ordered Simpson to come out of
the cell, and initially, Simpson complied. Thomas said that as
Simpson moved toward the door, he ordered Simpson to turn
around to be handcuffed, but Simpson resisted. Simpson
pushed Thomas onto the lower bunk and held him down by
the neck. Simpson grabbed Thomas’s pepper spray out of his
holster and somebody else took it from Simpson. Webb came
into the cell and pulled Simpson off of Thomas. Thomas said
that Simpson did not voluntarily let him up.

   After Webb pulled Simpson off of him, Thomas ordered
Simpson out of the cell and onto the ground, but Simpson did
not comply. Thomas grabbed Simpson in a bear hug and
forced him to the ground. After Simpson was on the ground,
Thomas got on Simpson’s back to hold him down and then
ordered him to put his hands behind his back. Simpson com-
plied. Thomas denied punching Simpson outside of the cell,
but said that he probably hit Simpson when he was trying to
get Simpson off of him. Webb testified that Thomas punched
Simpson while they were in the cell.

B.     The 115 Report

   A CMF disciplinary officer reported the incident in a 115
Rules Violation Report (“115 Report”). The hearing officer
found Simpson guilty of violating California Code of Regula-
tions tit. 15, § 3005(c) “for the specific act of battery on a
Peace Officer.” He then assessed Simpson 150 days of behav-
ioral credit forfeiture. The prison referred the case to the
Solano County District Attorney for possible felony prosecu-
tion, but the D.A. declined to file any charges. Simpson
6642                      SIMPSON v. THOMAS
sought habeas relief from the disciplinary hearing, but it was
denied as untimely.

C.     Motions in Limine

  1.    Motion One—Rule 609

   Prior to the trial in Simpson’s § 1983 suit, Simpson filed a
motion in limine to exclude evidence of his prior felonies.
The district court denied the motion and admitted evidence of
three prior felony convictions for: 1) burglary in 1986; 2) pos-
session of narcotics in 1989; and 3) possession of marijuana
in 1993. Although the record does not contain evidence of the
exact release dates on each of these convictions, a probation
report in the record indicates that all three convictions fall
outside the ten-year time limit of Federal Rule of Evidence
609(b).1

   The district court admitted the prior convictions in spite of
Rule 609(b)’s ten-year time limit because under California’s
Three Strikes Law, the prior convictions were “utilized by the
sentencing court when they made the determination to give
him [the sentence being served at the time of trial]” and thus
“those prior strikes were not and do not wash out . . . regard-
less of the fact that they may be older than ten years.” The
district court said also that “one of the things that’s utilized
by the institution to determine the level of security, classifica-
tion, location . . . is all based on the plaintiff’s prior felony con-
victions.”2
  1
     In January of 1987, Simpson was sentenced to forty months for the
1986 burglary. In January of 1990, he was sentenced to two years for the
1989 possession conviction. Finally, in March of 1994, he was sentenced
to sixteen months for the 1993 marijuana conviction. The trial in the pres-
ent case took place in March of 2007.
   2
     Thomas does not defend the district court’s evidentiary ruling on the
second ground.
                        SIMPSON v. THOMAS                 6643
  2.    Motion Two—Heck v. Humphrey

   Simpson sought to testify that Thomas punched him as
soon as he entered the cell, and that Simpson’s subsequent
actions were in self-defense. Citing Heck, 512 U.S. 477, the
district court granted Thomas’s motion in limine and refused
to allow Simpson to testify that Thomas had punched him first
because such testimony would invalidate the result of CMF’s
disciplinary proceeding against Simpson related to the inci-
dent. Both the district court and Thomas agreed that “[t]his
does not, however, foreclose Simpson from pursuing his alle-
gations that excessive force was used following his assault on
Sergeant Thomas.”

                               II

                 STANDARD OF REVIEW

   We review evidentiary rulings for abuse of discretion.
United States v. Plancarte-Alvarez, 366 F.3d 1058, 1062 (9th
Cir. 2004). We review de novo a district court’s interpretation
of the Federal Rules of Evidence. United States v. Sioux, 362
F.3d 1241, 1245 n.5 (9th Cir. 2004). The decision to exclude
evidence will be reversed only if it is “more likely than not
that the error affected the verdict.” United States v. Edwards,
235 F.3d 1173, 1178 (9th Cir. 2000). We review de novo pure
questions of law. United States v. Mateo-Mendez, 215 F.3d
1039, 1042 (9th Cir. 2000).

                               III

                         DISCUSSION

A.     Federal Rule of Evidence 609

  1.    Three Strikes

  [1] We are presented with an issue of first impression:
whether prior convictions more than ten years old may be
6644                  SIMPSON v. THOMAS
used for impeachment purposes under Federal Rule of Evi-
dence 609 (“Rule 609”) if those prior convictions are used to
enhance a sentence for a separate conviction that falls within
the ten-year time limit of Rule 609(b). We hold that such con-
victions do not endure for the purposes of Rule 609(b) and
therefore are not admissible against the witness, unless the
court determines “that the probative value of the conviction
supported by specific facts and evidence substantially out-
weighs its prejudicial effect.” See FED. R. EVID. 609(b). Fur-
thermore, we hold that in this case, it is more likely than not
that the admission of the convictions affected the verdict, and
therefore the case must be remanded for a new trial.

   [2] Rule 609(a)(1) provides “evidence that a witness other
than an accused has been convicted of a crime shall be admit-
ted, subject to Rule 403, if the crime was punishable by death
or imprisonment in excess of one year . . . .” Rule 609(a)(1)
is subject to the time limit of 609(b). Under 609(b), the evi-
dence of a conviction

    is not admissible if a period of more than ten years
    has elapsed since the date of the conviction or the
    release of the witness from the confinement imposed
    for that conviction, whichever is the later date,
    unless the court determines, in the interests of jus-
    tice, that the probative value of the conviction sup-
    ported by specific facts and circumstances
    substantially outweighs its prejudicial effect.

   [3] The district court erred in admitting the evidence of
Simpson’s three prior felony convictions. In United States v.
Kaluna, we addressed a challenge to the Federal Three Strikes
Provision, 18 U.S.C. § 3559(c)(1). 192 F.3d 1188, 1198-99
(9th Cir. 1999) (en banc). There, we declined to hold that such
a provision violated the Double Jeopardy Clause, observing
that “the enhanced punishment imposed for the later offense
is not to be viewed as either a new jeopardy or additional pen-
alty for the earlier crimes, but instead as a stiffened penalty
                       SIMPSON v. THOMAS                    6645
for the latest crime.” Id. (internal quotation marks omitted).
We believe that this same reasoning applies to California’s
Three Strikes Provision, Cal. Penal Code §§ 667, 1170.12.
See Allen v. Stratton, 428 F. Supp. 2d 1064, 1078 (C.D. Cal.
2006) (citing Witte v. United States, 515 U.S. 389, 400 (1995)
and holding that “the use of prior convictions to enhance a
later sentence under a recidivism statute, such as [Califor-
nia’s] Three Strikes law, does not offend double jeopardy
principles. . . .”).

   [4] In the present case, Simpson’s prior convictions
enhanced the length of his current conviction under Califor-
nia’s Three Strikes Provision. However, Witte, Kaluna, and
Allen preclude any conclusion other than that Simpson had
already completed his sentence for the prior convictions at the
time his current sentence was enhanced. If we were to adopt
the district court’s position and permit the use of prior convic-
tions older than ten years for impeachment purposes under
Rule 609, then the prior convictions would no longer be “a
stiffened penalty for the latest crime.” Witte, 515 U.S. at 400.

   [5] Furthermore, the plain language of 609(b) excludes evi-
dence of a conviction if it has been more than ten years “since
the date of the conviction or the release of the witness from
the confinement imposed for that conviction.” FED. R. EVID.
609(b) (emphasis added). We see no reason to construe this
language to mean anything other than exactly what it says.
Although the sentence Simpson was serving at the time of this
trial was admissible because that conviction fell within the
parameters of Rule 609(b), the three prior convictions were
not admissible because, at the time of trial, it had been more
than ten years since Simpson was released on the three prior
convictions. Thus, those prior convictions did not fall within
the plain language of Rule 609(b).

  2.   Probative Value

   [6] Although we conclude that the three prior convictions
are more than ten years old as defined in 609(b), they are still
6646                       SIMPSON v. THOMAS
admissible if the court determines “that the probative value of
the conviction supported by specific facts and circumstances
substantially outweighs its prejudicial effect.” Id. The com-
mittee notes to the 1974 Enactment to Rule 609(b) state:

      It is intended that convictions over 10 years old will
      be admitted very rarely and only in exceptional cir-
      cumstances . . . . requiring the court to make specific
      findings on the record as to the particular facts and
      circumstances it has considered in determining that
      the probative value of conviction substantially out-
      weighs the prejudicial effect.

   [7] The district court said that it did not find that the admis-
sion of the prior convictions “would be so prejudicial as to
outweigh the probative value.” This summary conclusion by
the district court was erroneous for three reasons. First, the
language used by the district court inverts the requirement of
Rule 609(b) by requiring the prejudice to outweigh the proba-
tive value. Second, the district court did not offer specific
facts and circumstances to support its conclusion, as required
by Rule 609(b). Third, the language of the Rule requires that
the probative value substantially outweighs the prejudice.3
Here the district court made no such determination.
  3
    We note also that our previous cases have set forth a list of factors a
district court should consider in a criminal case when determining whether
the probative value outweighs the prejudice. “These factors are: (1) the
impeachment value of the prior crime; (2) the point in time of the convic-
tion and the witness’s subsequent history; (3) the similarity between the
past crime and the charged crime; (4) the importance of defendant’s testi-
mony; and (5) the centrality of defendant’s credibility.” United States v.
Hursh, 217 F.3d 761, 768 (9th Cir. 2000). Nothing in the record indicates
that the district court considered any of these factors. Although we have
never held that such factors should be considered in a civil case, and do
not do so here, we think that, under the circumstances of this case, consid-
eration of these factors by the district court on remand would be appropri-
ate.
                         SIMPSON v. THOMAS                       6647
  [8] Based on the foregoing, we conclude that the admission
of the convictions was an abuse of discretion.

  3.     Affect on the Outcome of the Trial

   [9] In order for us to conclude that the admission of the
prior convictions warrants reversal, we must be persuaded
that their admission affected the outcome of the trial.
Edwards, 235 F.3d at 1178. We have previously held that it
was not harmless error to admit evidence of prior convictions
where

       the result in the case turned almost entirely on the
       relative credibility of the party-witnesses. Juries
       often view citizens’ claims of police abuse with
       skepticism. In this context, the improper introduction
       of evidence that [the plaintiff] had been a juvenile
       offender and had been convicted of a felony as an
       adult was clearly prejudicial to his chances of receiv-
       ing fair consideration from the jury.

Powell v. Levit, 640 F.2d 239, 241 (9th Cir. 1981).

   [10] As in Powell, the result in this case turned almost
entirely on the credibility of the witnesses—it came down to
whether the jury believed the testimony of Thomas and the
other guards or the testimony of Simpson and his fellow
inmates. We conclude that it is more likely than not that
admitting the conviction affected the verdict because,
although the jurors would have known Simpson was in prison
for at least one felony, the knowledge that he had at least
three other felony convictions likely prejudiced the jury
against Simpson and made them more likely to question his
credibility.

  [11] Because the district court improperly admitted evi-
dence of convictions outside the ten-year limit of Rule 609(b)
and did not properly perform the balancing test required by
6648                   SIMPSON v. THOMAS
Rule 609(b), and because it was more likely than not the
admission of the convictions affected the verdict, we reverse
and remand for a new trial.

B.     Heck v. Humphrey

   [12] We turn next to yet another issue of first impression
in this circuit: whether Heck v. Humphrey may be used to bar
evidence in a § 1983 claim for excessive force. We conclude
that Heck does not create a rule of evidence exclusion. There-
fore, if, as in this case, a party is permitted to proceed on a
§ 1983 claim, relevant evidence may not be barred under the
rule announced in Heck.

   In order to reach our ultimate conclusion, we first examine
the relationship between § 1983 and the habeas corpus statute,
28 U.S.C. § 2254, and United States Supreme Court cases
addressing the use of § 1983 to challenge prison administra-
tive decisions. Section 1983 provides:

     Every person who, under color of any statute, ordi-
     nance, regulation, custom, or usage, of any State or
     Territory or the District of Columbia, subjects, or
     causes to be subjected, any citizen of the United
     States or other person within the jurisdiction thereof
     to the deprivation of any rights, privileges, or immu-
     nities secured by the Constitution and laws, shall be
     liable to the party injured in an action at law, suit in
     equity, or other proper proceeding for redress, except
     that in any action brought against a judicial officer
     for an act or omission taken in such officer’s judicial
     capacity, injunctive relief shall not be granted unless
     a declaratory decree was violated or declaratory
     relief was unavailable. For the purposes of this sec-
     tion, any Act of Congress applicable exclusively to
     the District of Columbia shall be considered to be a
     statute of the District of Columbia.
                       SIMPSON v. THOMAS                         6649
42 U.S.C. § 1983. Section 2254(b), in relevant part, provides:

    An application for a writ of habeas corpus on behalf
    of a person in custody pursuant to the judgment of
    a State court shall not be granted unless it appears
    that . . . the applicant has exhausted the remedies
    available in the courts of the State; or . . . there is an
    absence of available State corrective process; or . . .
    circumstances exist that render such process ineffec-
    tive to protect the rights of the applicant.

28 U.S.C. § 2254.

  [13] We have previously outlined the potential conflict
between §§ 1983 and 2254 in Ramirez v. Galaza, 334 F.3d
850 (9th Cir. 2003). There we summarized the conflict as fol-
lows:

       While the Civil Rights Act of 1871 . . . and the
    federal habeas corpus statute . . . both provide access
    to the federal courts “for claims of unconstitutional
    treatment at the hands of state officials, . . . they dif-
    fer in their scope and operation.” Heck, 512 U.S. at
    480 . . . . Section 1983 provides a remedy for injuries
    caused by violations of federal law by persons acting
    under the color of state law. “Congress’s purpose in
    enacting § 1983 was to create a novel civil remedy
    for violation of established constitutional rights.”
    Martinez v. City of Oxnard, 270 F.3d 852, 856 n.2
    (9th Cir. 2001). Given this unique legislative intent
    to provide a federal forum for the vindication of fed-
    eral rights, courts historically declined to require
    § 1983 plaintiffs to exhaust state remedies. Congress
    altered this tradition in 1996 with the enactment of
    the Prison Litigation Reform Act by requiring pris-
    oners to exhaust all available administrative reme-
    dies before filing a § 1983 action. 42 U.S.C.
    § 1997e(a) . . . .
6650                  SIMPSON v. THOMAS
       In contrast, the federal habeas corpus statute
    explicitly requires state prisoners to first seek relief
    in a state forum. 28 U.S.C. § 2254(b). This exhaus-
    tion requirement “is rooted in considerations of
    federal-state comity,” and allows “the state court
    system that has convicted a defendant the first
    opportunity . . . to correct the errors made in the
    internal administration of their prisons.” Preiser v.
    Rodriguez, 411 U.S. 475, 491-92 . . . (1973). The
    burden of satisfying the exhaustion requirement of
    § 2254, and the absence of a similar restriction in
    § 1983, left the two statutes on a “collision course.”
    Heck, 512 U.S. at 492 . . . (Souter, J., concurring in
    the judgment).

334 F.3d at 854-55 (internal citations and footnotes omitted).
Thus, as we explained in Ramirez, there is potential for con-
flict between the two statutes.

   We turn next to a summary of the United States Supreme
Court cases addressing this conflict. The Court first addressed
the potential conflict between § 1983 and § 2254 in Preiser v.
Rodriguez, 411 U.S. 475 (1973). In Preiser, following prison
disciplinary proceedings leading to the deprivation of good-
time credits, prisoners brought suit under § 1983 challenging
the constitutionality of the disciplinary proceedings. 411 U.S.
at 476-77. The Court explained:

    The broad language of § 1983, however, is not con-
    clusive of the issue before us. The statute is a general
    one, and, despite the literal applicability of its terms,
    the question remains whether the specific federal
    habeas corpus statute, explicitly and historically
    designed to provide the means for a state prisoner to
    attack the validity of his confinement, must be
    understood to be the exclusive remedy available in
    a situation like this where it so clearly applies.
                      SIMPSON v. THOMAS                    6651
Id. at 489. The Court further explained that in contrast to
§ 1983, § 2254 requires the exhaustion of state remedies. Id.
at 489-91. The Court continued: “The strong considerations of
comity that require giving a state court system that has con-
victed a defendant the first opportunity to correct its own
errors thus also require giving the States the first opportunity
to correct the errors made in the internal administration of
their prisons.” Id. at 492. Thus, the court concluded that a
state prisoner cannot use a § 1983 action to challenge “the
fact or duration of his confinement,” id. at 489, because such
an action lies at “the core of habeas corpus,” id. at 487.

   In Wolff v. McDonnell, 418 U.S. 539 (1974), the Court took
on the issue of whether prisoners could use § 1983 to obtain
restoration of good-time credits and damages. 418 U.S. at
553-54. The Court reaffirmed its holding in Preiser and held
that the prisoners could not seek restoration of good-time
credits under § 1983 because restoration of good-time credits
challenged “the very fact or duration of their confinement.”
Id. at 554. However, the Court permitted the prisoners to use
§ 1983 to obtain a declaratory judgment “as a predicate to a
damages award,” explaining that Preiser did not bar such a
claim “and because under [Preiser] only an injunction restor-
ing good time improperly taken is foreclosed, neither would
it preclude a litigant with standing from obtaining by way of
ancillary relief an otherwise proper injunction enjoining the
prospective enforcement of invalid prison regulations.” Id. at
554-55.

   Twenty years later, the Court revisited the relationship
between § 1983 and § 2254 in Heck. In Heck, a prisoner initi-
ated a § 1983 action seeking damages but not release from
custody. 512 U.S. at 478-79. The prisoner alleged that the
defendants—prosecutors and a police officer—destroyed evi-
dence, used unlawful identification procedures, and employed
improper investigative techniques, resulting in the prisoner’s
conviction and imprisonment. Id. at 479. The Court affirmed
the dismissal of the suit, holding that
6652                   SIMPSON v. THOMAS
    in order to recover damages for allegedly unconstitu-
    tional conviction or imprisonment, or for other harm
    caused by actions whose unlawfulness would render
    a conviction or sentence invalid, a § 1983 plaintiff
    must prove that the conviction or sentence has been
    reversed on direct appeal, expunged by executive
    order, declared invalid by a state tribunal authorized
    to make such determination, or called into question
    by a federal court’s issuance of a writ of habeas cor-
    pus, 28 U.S.C. § 2254.

Id. at 486-87 (internal footnote omitted). The Court explained
that “when a state prisoner seeks damages in a § 1983 suit, the
district court must consider whether a judgment in favor of
the plaintiff would necessarily imply the invalidity of his con-
viction or sentence.” Id. at 487. “But if the district court deter-
mines that the plaintiffs action, even if successful, will not
demonstrate the invalidity of any outstanding criminal judg-
ment against the plaintiff, the action should be allowed to pro-
ceed, in the absence of some other bar to the suit.” Id.
(internal footnote omitted).

   Since the inception of the rule in Heck, the Court has only
addressed this issue a few times, and in none of those cases
did the Court address the use of Heck to bar evidence. For
example, in Edwards v. Balisok, 520 U.S. 641, 643 (1997),
the Court applied Heck to a § 1983 claim for damages and
declaratory relief brought by a state prisoner challenging the
validity of the procedures used to deprive him of good-time
credits. There, it explained that “[t]he principal procedural
defect complained of by [plaintiff] would, if established, nec-
essarily imply the invalidity of the deprivation of his good-
time credits.” 520 U.S. at 646. Consequently, the Court held
the claim was not cognizable under § 1983. Id. at 648.

  More recently, in Wilkinson v. Doston, 544 U.S. 74, 76
(2005) the Court addressed the issue of whether two prisoners
could seek injunctive and declaratory relief pursuant to
                      SIMPSON v. THOMAS                        6653
§ 1983 when challenging Ohio’s state parole procedures. The
Court summarized its prior consideration of the interplay
between §§ 1983 and 2254:

       Throughout the legal journey from Preiser to
    Balisok, the Court has focused on the need to ensure
    that state prisoners use only habeas corpus (or simi-
    lar state) remedies when they seek to invalidate the
    duration of their confinement-either directly through
    an injunction compelling speedier release or indi-
    rectly through a judicial determination that necessar-
    ily implies the unlawfulness of the State’s custody.
    Thus, Preiser found an implied exception to
    § 1983’s coverage where the claim seeks-not where
    it simply “relates to”-“core” habeas corpus relief,
    i.e., where a state prisoner requests present or future
    release. Wolff makes clear that § 1983 remains avail-
    able for procedural challenges where success in the
    action would not necessarily spell immediate or
    speedier release for the prisoner. Heck specifies that
    a prisoner cannot use § 1983 to obtain damages
    where success would necessarily imply the unlawful-
    ness of a (not previously invalidated) conviction or
    sentence. And Balisok, like Wolff, demonstrates that
    habeas remedies do not displace § 1983 actions
    where success in the civil rights suit would not nec-
    essarily vitiate the legality of (not previously invali-
    dated) state confinement. These cases, taken
    together, indicate that a state prisoner’s § 1983
    action is barred (absent prior invalidation)-no matter
    the relief sought (damages or equitable relief), no
    matter the target of the prisoner’s suit (state conduct
    leading to conviction or internal prison proceedings)-
    if success in that action would necessarily demon-
    strate the invalidity of confinement or its duration.

544 U.S. at 81-82 (internal citation omitted). Thus, the Court
concluded, the prisoners’ claims in Wilkinson were cognizable
under § 1983 because
6654                   SIMPSON v. THOMAS
    Success for Dotson does not mean immediate release
    or a shorter stay in prison; it means at most new eli-
    gibility review, which at most may speed consider-
    ation of a new parole application. Success for
    Johnson means at most a new parole hearing at
    which Ohio parole authorities may, in their discre-
    tion, decline to shorten his prison term. Because nei-
    ther prisoner’s claim would necessarily spell
    speedier release, neither lies at “the core of habeas
    corpus.”

Id. at 82 (internal citations omitted).

   [14] None of these Supreme Court cases specifically
address or even imply that Heck may serve as an evidentiary
bar. Rather, we believe that this entire line of cases and
repeated discussions of the interplay between § 1983 and
§ 2254 demonstrate that the Supreme Court’s intent in
announcing the rule in Heck was to prevent prisoners from
subverting the requirements of § 2254 by filing suit under
§ 1983. Consequently, all of these cases discuss whether a
claim itself is viable, not whether evidence is admissible.

   [15] Since Heck was decided, we too have frequently con-
sidered its implications on § 1983 cases. See, e.g., Smith v.
City of Hemet, 394 F.3d 689 (9th Cir. 2005) (en banc);
Ramirez, 334 F.3d 850; Cunningham v. Gates, 312 F.3d 1148
(9th Cir. 2003) (as amended); Sanford v. Motts, 258 F.3d
1117 (9th Cir. 2001); Butterfield v. Bail, 120 F.3d 1023 (9th
Cir. 1997); Smithart v. Towery, 79 F.3d 951 (9th Cir. 1996).
However, like the Supreme Court, we have never held or even
implied that Heck could be used to bar evidence—rather,
applying Supreme Court precedent, we have repeatedly con-
sidered whether Heck bars a claim under § 1983.

  In addition to our analysis above, we find support for our
decision in criminal cases permitting evidence relating to past
acquittals to be used in a present criminal case. For example,
                      SIMPSON v. THOMAS                    6655
in Dowling v. United States, 493 U.S. 342 (1990), the
Supreme Court held that it was not a violation of the Double
Jeopardy Clause or the Due Process Clause to admit testi-
mony regarding the circumstances of a prior crime of which
the defendant had been acquitted. 493 U.S. at 343-44.

   In that case, the suspect was on trial for bank robbery and
armed robbery. Id. at 344. The government introduced testi-
mony under Federal Rule of Evidence 404(b) by the victim in
a robbery that the defendant was acquitted of in an earlier
trial. Id. at 344-45. The victim identified the defendant as one
of the alleged robbers in the prior robbery and described the
mask he was wearing and the gun he was carrying during the
robbery. Id. She identified also another suspect in the first
robbery, and that suspect was suspected of acting as the get-
away car driver in the second robbery. Id.

   The government claimed that the twin purposes of the testi-
mony were: 1) to strengthen its identification of the defendant
as the bank robber in the second case because the victim in
the first case described a suspect wearing a mask and carrying
a gun similar to that used in the second case; and 2) to link
the defendant to the alleged getaway car driver in the second
case. Id. at 345.

   The defendant argued that under the collateral-estoppel
doctrine, his prior acquittal precluded the government from
introducing the testimony. Id. at 348. The Court rejected this
argument, defining “the collateral-estoppel doctrine as provid-
ing that when an issue of ultimate fact has once been deter-
mined by a valid and final judgment, that issue cannot again
be litigated between the same parties in any future lawsuit.”
Id. at 347 (quotation marks omitted). It went on to explain
that because “the prior acquittal did not determine an ultimate
issue in the present case” and because the government was not
required to prove beyond a reasonable doubt in the second
robbery that the defendant was the suspect in the first robbery,
6656                   SIMPSON v. THOMAS
“the collateral estoppel component of the Double Jeopardy
Clause is inapposite.” Id. at 349.

   Although the collateral-estoppel component of the Double
Jeopardy Clause does not bear directly on the issue in the case
at bar, we believe that the Court’s holding in Dowling sup-
ports our determination that evidence is not barred merely
because a claim may be. As in Dowling, the burden of proof
is different in Simpson’s civil case than it was in the prison
administrative proceeding finding him guilty of battery. Fur-
thermore, whether Thomas punched Simpson as soon as
Thomas entered the cell was not “an issue of ultimate fact”
determined in a valid and final judgment in the prison admin-
istrative proceeding. See id. at 347. In short, the results of the
administrative proceeding fall short of the stricter Heck
requirement that the claims asserted would “necessarily
imply” or “demonstrate” the invalidity of the conviction.

   [16] In light of our analysis of Supreme Court precedent
relating to Heck, §§ 1983 and 2254, we hold that Heck is not
an evidentiary doctrine. Therefore, we reverse and remand for
a new trial. We conclude that even if the district court deter-
mines on remand that Simpson may not file a § 1983 lawsuit
relating to any injuries stemming from Thomas’s alleged
punch upon entering the cell, Simpson is still entitled to tell
the jury the entire story—in other words, he may present evi-
dence and/or testimony that Thomas initiated the physical
confrontation in the cell by punching Simpson.

                               IV

                        CONCLUSION

  Because the district court improperly admitted evidence
under Rule 609(b) and improperly barred evidence under
                        SIMPSON v. THOMAS                       6657
Heck, we reverse and remand for a new trial.4

  REVERSED and REMANDED.




  4
    In light of our holdings, we need not address the remaining issues
raised by Simpson.
