                                In the

    United States Court of Appeals
                 For the Seventh Circuit
No. 12-1415

UNITED STATES OF AMERICA,
                                                     Plaintiff-Appellee,

                                   v.

MARVIN CHAPMAN,
                                                 Defendant-Appellant.

            Appeal from the United States District Court
        for the Northern District of Illinois, Eastern Division.
            No. 10 CR 783 — Virginia M. Kendall, Judge.


  ARGUED NOVEMBER 28, 2012 — DECIDED AUGUST 28, 2014



   Before WOOD, Chief Judge, and KANNE and SYKES, Circuit
Judges.
    SYKES, Circuit Judge. On a foggy night in Chicago, police
officers patrolling the west side of the city spotted Marvin
Chapman walking down a sidewalk carrying a bag with what
looked like the barrel of a rifle protruding from it. As the
officers approached, Chapman ducked into an abandoned
duplex. One officer followed Chapman into the house and saw
him drop the bag in the living room; another caught up with
2                                                   No. 12-1415

Chapman as he tried to escape through a bedroom window. In
the bag they found a distribution quantity of heroin and an
assault rifle.
    Chapman was charged with three crimes: possessing heroin
with intent to distribute, possessing a firearm in furtherance of
a drug-trafficking crime, and possessing a firearm as a felon. At
trial he claimed that the officers were either mistaken or lying
about having seen him carrying the bag. He testified that he
did not possess the bag at any time; it was either in the
building before he entered or was planted there. His girlfriend,
who was present and witnessed these events, also testified that
he was not carrying a bag. The jury returned a factually
inconsistent verdict, convicting Chapman of possessing the
drugs but acquitting him on the two gun-possession counts.
    Chapman challenges his conviction on three grounds. First,
he contends that the judge erroneously admitted the details of
his prior heroin-trafficking conviction under Rule 404(b) of the
Federal Rules of Evidence for the purpose of proving that he
knew how heroin is packaged and intended to distribute the
drugs found in the bag. Second, he argues that the judge
erroneously precluded him from explaining his six prior felony
convictions. The convictions (though not their factual details)
were admitted for impeachment purposes. Chapman wanted
to blunt the impact of this evidence by telling the jury that he
had pleaded guilty and accepted responsibility in his earlier
cases, but the judge wouldn’t allow it. Finally, Chapman
challenges the judge’s refusal to compel the testimony of an
eyewitness who might have supported his version of events.
The witness was facing drug charges in a separate case and
No. 12-1415                                                  3

invoked his Fifth Amendment privilege against self-
incrimination. Chapman insists that the witness had no
legitimate fear of self-incrimination and should have been
required to testify.
    We agree with Chapman’s first claim of error: The judge
should not have admitted the details of Chapman’s heroin-
trafficking conviction under Rule 404(b). As explained in our
recent en banc opinion in United States v. Gomez, No. 12-1104,
2014 WL 4058963 (7th Cir. Aug. 18, 2014) (en banc), evidence of
other bad acts is inadmissible to show character or propensity
but may be admitted for another purpose provided that the
evidence is relevant under a theory that does not rely on an
inference about the actor’s propensity. See FED. R. EVID.
404(b)(1). Here, the judge allowed the government to use the
specifics of Chapman’s prior heroin conviction to prove
knowledge and intent, but the relevance of the evidence on
those issues depends entirely on a forbidden propensity
inference. Even if the evidence was relevant in a non-
propensity way, its probative value was substantially out-
weighed by the risk of unfair prejudice given that Chapman’s
defense was that he did not possess the bag at all. See FED. R.
EVID. 403. The jury’s inconsistent verdict shows that the Rule
404(b) error was not harmless.
   That alone requires remand for retrial. For completeness,
however, we also conclude that the judge wrongly excluded
Chapman’s rehabilitation testimony but properly accepted the
eyewitness’s invocation of his privilege against self-
incrimination.
4                                                     No. 12-1415



                         I. Background
   Chapman has a long criminal record and has spent much of
his adult life incarcerated. When the events in this case
transpired, he had been out of jail for only about a month.
    On the evening of March 8, 2010, a heavy fog enveloped the
City of Chicago. The Chicago Weather Center reported dense
fog at 11:06 p.m. Other weather records established that
visibility was 0.1 miles or less, causing the cancellation of
around 90 flights at Chicago airports. One defense eyewitness
described the fog as thick. In contrast the Chicago police
officers involved in Chapman’s arrest—Officers McHale,
Lipka, McGrory, and Bouch—did not remember any fog that
night.
    The four officers testified that they were on patrol in an
unmarked squad car near the corner of Ohio Street and
Ridgeway Avenue on the city’s west side when they spotted
Chapman walking south on Ridgeway. The officers were
driving east on Ohio and observed Chapman from a distance
of about 150 feet (at the farthest point) to 25 feet (at the nearest
point). They testified that Chapman was carrying a dark-
colored bag with a cylindrical object—a rifle, they thought—
sticking out of it. When Chapman saw the approaching
officers, he fled into an abandoned two-flat building at
619 North Ridgeway.
   Chapman’s account differs. He testified that he was
standing on the street near the intersection of Ohio Street and
Ridgeway Avenue with his girlfriend, Damuriel Collier. With
No. 12-1415                                                  5

them was Derrick Lewis, an alleged drug dealer also known as
“D.C.” Collier, who also testified at Chapman’s trial, admitted
that she was talking to Lewis about selling cocaine for him.
When they saw the unmarked police car approaching, Chap-
man and Collier walked into the abandoned flat, and Lewis
walked away in another direction. Chapman and Collier both
testified that at no time—either before or after entering the
building—did Chapman possess a bag.
    As Chapman and Collier disappeared into the house,
Officers McHale and Lipka jumped from the patrol car and
gave chase. McHale ran around the side of the house and
down a gangway, while Lipka entered the house through the
front door. The building was unlit, but Lipka carried a flash-
light. He testified that he saw Chapman drop the bag in the
living room and then attempt to jump out of a bedroom
window. He also recalled hearing a “thud” as the bag hit the
ground. Lipka alerted McHale, who saw Chapman coming
through the window and detained him.
    Chapman’s account again differs. Chapman and Collier
testified that a police officer with a flashlight banged on the
front door of the house, and Collier opened the door for him.
Collier also said she heard breaking glass in the rear of the
building. They agreed that Chapman jumped—or tried to
jump—from a window.
    Chapman also introduced evidence that Officer McHale’s
account was not physically possible. A photo taken sometime
after Chapman’s arrest showed a rusted and partially broken
fence blocking the gangway that McHale said he used to access
the side of the building; a similar photo taken sometime before
6                                                    No. 12-1415

the arrest also showed a fence blocking the passageway. Collier
testified that the fence was in place on the night of Chapman’s
arrest. Putting this evidence together, Chapman argued that
the fence was blocking the gangway on March 8, 2010, and
McHale could not possibly have accessed the passageway as he
claimed.
    There were other unexplained discrepancies as well. Collier
testified that the police handcuffed her at the scene, put her in
a police vehicle, questioned her, and eventually let her go.
Officer McHale testified that no female witness was taken into
custody. Collier is not listed as a witness on any police report.
    Officer Lipka searched the bag (on closer inspection, it
turned out to be a dark blue laundry bag) and found a loaded
AR-15 assault rifle and two plastic bags containing 28 foil
packages of heroin, slightly over 10 grams in total weight. No
fingerprints were found on the gun, and the few usable prints
on the drug packaging did not match Chapman’s. One of the
officers searched Chapman and found three small bags of
marijuana and $9 in cash.
   The officers recalled that another female was present in the
abandoned house, but only one of them spoke with her. After
determining that she was not a safety concern, the officer told
her to leave. No police report mentions this woman.
    Chapman was indicted for possessing heroin with intent to
distribute, 21 U.S.C. § 841(a)(1); possessing a firearm in
furtherance of a drug-trafficking crime, 18 U.S.C. § 924(c)(1)(A);
and possessing a firearm as a felon, id. § 922(g)(1). His theory
of defense was that he never possessed the bag, let alone the
drugs and gun inside it. He claimed that he never physically
No. 12-1415                                                     7

held the bag, never controlled it, and prior to his arrest had
never seen it before. It was either already in the abandoned
house when he entered or it was planted.
    Before trial the government moved to admit the details of
Chapman’s 2006 conviction for possessing heroin with intent
to distribute for the purpose of proving Chapman’s knowledge
and intent. The government planned to cross-examine
Chapman about his six prior felony convictions for impeach-
ment purposes as permitted under Rule 609, but the motion in
limine sought permission to introduce the specifics of the 2006
heroin-trafficking conviction as substantive evidence under
Rule 404(b).
   Chapman responded that his knowledge and intent were
not really at issue because his defense was that he never
possessed the bag in the first place. He offered to stipulate that
the heroin found in the bag was distribution quantity, so
whoever possessed it intended to distribute the drugs. Under
these circumstances, he explained, the only purpose for
admitting this evidence would be to show that he had a
propensity for dealing heroin.
    The judge granted the government’s motion, apparently
under the impression that Chapman was denying that he
intended to possess or distribute the heroin found in the bag.
The government extensively cross-examined Chapman about
the specifics of his 2006 heroin conviction. Some of the prosecu-
tor’s questions elicited testimony about Chapman’s familiarity
with heroin packaging; others asked about the mechanics of
selling the drug.
8                                                  No. 12-1415

    The government also impeached Chapman with his six
prior felony convictions. Consistent with the requirements of
Rule 609, however, these questions were limited to the fact that
he had been convicted of crimes. Still, this line of inquiry
featured prominently in the government’s cross-examination.
For example, the prosecutor’s first question to Chapman was,
“Sir, you’re a drug dealer?” Other questions included:
“Mr. Chapman, is it fair to say that you are a criminal who’s
been convicted of both drugs and violence?” And, “Wouldn’t
it be fair to say that you’re a six-time convicted felon?”
    In an attempt at rehabilitation, defense counsel sought to
elicit testimony from Chapman that he had pleaded guilty in
each of his prior cases because he was in fact guilty. The point
was to set up an argument that Chapman’s acceptance of
responsibility was suggestive of honesty, minimizing the
harmful effect of his criminal record on his credibility. The
judge sustained the government’s objection and disallowed
this line of questioning.
    Chapman’s counsel also subpoenaed Lewis to testify about
the events of March 8, expecting him to corroborate
Chapman’s and Collier’s testimony that they were standing on
the street near the abandoned duplex when the police arrived
at the scene and that Chapman did not have a bag with him.
But Lewis was facing charges of drug dealing stemming from
his own arrest on March 9, 2010. He invoked his Fifth Amend-
ment privilege against self-incrimination.
   Chapman asked the judge to compel Lewis’s testimony,
assuring the court and Lewis’s counsel that direct examination
would entail only a few questions and would concentrate on
No. 12-1415                                                 9

whether Chapman was carrying a bag. This limited line of
inquiry, Chapman insisted, would not raise the possibility of
self-incrimination. Lewis’s attorney, with support from the
government, continued to resist the subpoena, explaining that
even if Chapman’s direct examination would not risk self-
incrimination, the government’s cross-examination very well
might. For example, any questions about his use of the nick-
name “D.C.” could be self-incriminating in his own case
because his use of aliases was at issue there. And the govern-
ment might also question him about whether he had been
talking to Collier about selling drugs.
    In response to these concerns, Chapman suggested that the
court limit the government’s cross-examination. The judge
rejected this solution, holding instead that Lewis had a good-
faith fear of self-incrimination and could not be compelled to
testify. Chapman asked the court to require Lewis to take the
witness stand and invoke his Fifth Amendment privilege in
front of the jury. The judge rejected this request as well and
released Lewis from the subpoena.
    The jury returned an inconsistent verdict, convicting
Chapman of possessing heroin with intent to distribute but
acquitting him on the two firearm counts. The court imposed
a sentence of 210 months, and this appeal followed.


                       II. Discussion
A. Admission of Other-Act Evidence
  Chapman first challenges the district court’s decision to
admit the specifics of his 2006 conviction for possession of
10                                                  No. 12-1415

heroin with intent to distribute. He argues that this evidence
served no purpose other than to show that he had a propensity
to deal heroin, in violation of the prohibition in Rule 404(b)
against using other-act evidence to prove propensity. Alterna-
tively, he argues that this evidence should have been excluded
under Rule 403.
     As we explained in our recent en banc decision in Gomez:
            Rule 404(b) excludes relevant evidence of
        other crimes, wrongs, or acts if the purpose is to
        show a person’s propensity to behave in a certain
        way, but other-act evidence may be admitted for
        “another purpose,” including, but not limited to,
        “proving motive, opportunity, intent, prepara-
        tion, plan, knowledge, identity, absence of mis-
        take, or lack of accident.”
2014 WL 4058963, at *6 (quoting FED. R. EVID. 404(b)(2)). We
also repeated some earlier cautionary words about admitting
evidence of a defendant’s other drug-related crimes in a drug
prosecution like this one: “Especially in drug cases … , other-
act evidence is too often admitted almost automatically,
without consideration of the ‘legitimacy of the purpose for
which the evidence is to be used and the need for it.’” Id. at *4
(quoting United States v. Miller, 673 F.3d 688, 692 (7th Cir.
2012)).
   We explained what the proponent of other-act evidence
must do in any case—whether drug-related or otherwise—to
win a favorable ruling on its admissibility:
No. 12-1415                                                             11

        [I]t’s not enough for the proponent of the other-
        act evidence simply to point to a purpose in the
        “permitted” list and assert that the other-act
        evidence is relevant to it. Rule 404(b) is not just
        concerned with the ultimate conclusion, but also
        with the chain of reasoning that supports the
        non-propensity purpose for admitting the evi-
        dence. In other words, the rule allows the use of
        other-act evidence only when its admission is
        supported by some propensity-free chain of
        reasoning.
Id. at *7 (citation omitted). Moreover, Gomez emphasized that
even if the proponent of the other-act evidence can establish its
relevance to a non-propensity purpose in a propensity-free
way, the district court “must in every case assess whether the
probative value of the other-act evidence is substantially
outweighed by a risk of unfair prejudice and may exclude the
evidence under Rule 403 if the risk is too great.” Id. at *11.
    Rule 403 balancing, we noted, is especially important in the
context of other-act evidence, which “raises special concerns
about unfair prejudice because it almost always carries some
risk that the jury will draw the forbidden propensity infer-
ence.”1 Id. at *8. Accordingly, the trial judge’s Rule 403 balanc-
ing of the probative value of the evidence against the risk of


1
 Rule 403 applies to all evidence and gives the court discretion to exclude
otherwise relevant evidence “if its probative value is substantially
outweighed by a danger of … unfair prejudice, confusing the issues,
misleading the jury, undue delay, wasting time, or needlessly presenting
cumulative evidence.”
12                                                   No. 12-1415

unfair prejudice “does much of the heavy lifting in the admissi-
bility analysis by excluding other-act evidence that may be
slightly probative through a non-propensity theory but has a
high likelihood of creating unfair prejudice by leading a jury to
draw conclusions based on propensity.” Id.
    Here, the district court permitted the government to
introduce the details of Chapman’s 2006 conviction for heroin
trafficking for the purpose of proving that he knew the
substance found in the bag was heroin (based on familiarity
with its packaging) and possessed the drugs with intent to
distribute them. There are two problems with this theory of
admissibility. First, the details of the prior heroin conviction
are relevant to Chapman’s knowledge and intent only through
a paradigmatic inference about propensity: because Chapman
sold heroin before he must have intended to do so again in this
instance.
    Second, even if the government had articulated a theory of
relevance that does not rely on an impermissible propensity
inference (and it did not), the probative value of the heroin-
trafficking conviction is substantially outweighed by the risk of
unfair prejudice in the specific context of this case. Chapman’s
defense rested entirely on his claim that he never possessed the
bag at all. His knowledge of heroin packaging was a red
herring. He never argued that he didn’t recognize the sub-
stance in the bag as heroin; instead, he claimed that he did not
possess the bag, period.
    It’s true that Chapman’s intent was formally “at issue”
because the drug charge in this case—possession with intent to
distribute—is a specific-intent crime. See id. at *10–11. Even so,
No. 12-1415                                                     13

as we explained in Gomez, the degree to which the non-
propensity fact for which the other-act evidence is admitted
actually is contested in the case is an important factor in the
court’s assessment of the probative value of the evidence under
Rule 403. Id. at *11. Accordingly, we held that meaningful
Rule 403 balancing “should take account of the extent to which
the non-propensity fact for which the [other-act] evidence is
offered actually is at issue in the case.” Id. That did not happen
here.
    Indeed, Chapman offered to stipulate that the heroin in the
bag was distribution quantity so that whoever possessed the
bag intended to distribute the drugs that were found in it.
Although “the prosecution is entitled to prove its case free
from any defendant’s option to stipulate the evidence away,”
Old Chief v. United States, 519 U.S. 172, 189 (1997), Chapman’s
theory of defense and his offer to stipulate that the drugs were
distribution quantity significantly affected the Rule 403 bal-
ance. With intent basically uncontested, the risk of unfair
prejudice took on greater significance. And although the court
gave the jury a limiting instruction, the temptation to draw an
impermissible propensity inference was great.
    The facts of United States v. Miller closely track the facts of
this case. There the government found drugs in a room where
Miller was alleged to be staying and accused him of possessing
them with intent to distribute. 673 F.3d at 694. Miller did not
dispute that the drugs were packaged for distribution, but
rather flatly denied that the drugs were his or that he was even
staying in the room where they were found. Id. at 696. The
district court allowed the government to introduce the details
14                                                 No. 12-1415

of Miller’s past drug-distribution convictions for the purpose
of proving intent. We found reversible error. Id. at 700 (“The
relevance of the prior conviction here boils down to the
prohibited ‘once a drug dealer, always a drug dealer’ argu-
ment.”).
    We reach the same conclusion here. The government insists
that the Rule 404(b) error did not contribute to the verdict and
so was harmless. That argument contradicts the government’s
earlier explanation for the jury’s inconsistent verdict. At
sentencing Chapman’s counsel reminded the court that the
jury had returned a factually inconsistent verdict. The govern-
ment responded by rationalizing the inconsistency by reference
to the effectiveness of the Rule 404(b) evidence:
           As the Court recalls, there were — there was
       the testimony of four law enforcement officers.
       However, on the gun count, that was uncorrobo-
       rated by other evidence. However, on the drug
       count, there was some additional evidence,
       namely, there was 404(b) evidence, which the
       jury was allowed to consider for certain pur-
       poses, and that evidence went to the drug
       charge. And there was also the testimony of
       Mr. Chapman himself and his prior drug deal-
       ing.
          So it’s the Government’s position that while
       the jury found that it met its burden of proof on
       the drug charge, it obviously did not find that
       the Government had met its burden on the gun
       charges.
No. 12-1415                                                    15

    We think the government’s earlier position is the correct
one. The prosecution’s evidence was essentially the same
across the drug and gun charges, with the notable exception of
the erroneously admitted other-act evidence, which had a
bearing on the count on which the jury convicted—the drug
charge—but not on the gun counts on which Chapman was
acquitted. It’s hard to imagine a better indicator that the
Rule 404(b) error swayed the jurors. The test for harmless error
in this context is “whether, in the mind of the average juror, the
prosecution’s case would have been significantly less persua-
sive had the improper evidence been excluded.” Gomez, 2014
WL 4058963, at *15 (quoting United States v. Vargas, 689 F.3d
867, 875 (7th Cir. 2012)). The jury’s factually inconsistent
verdict is strong evidence that the government’s case would
have been significantly less persuasive without the other-act
evidence.
    Even aside from the inconsistent verdict, the remaining
evidence was not so overwhelming that we can say with
confidence that the Rule 404(b) error was harmless. The officers
initially observed Chapman from a distance through a dense
fog, which they professed not to recall, casting some doubt on
their testimony. Chapman’s flight from the police is suggestive
of guilt but far from conclusive, especially in light of
Chapman’s criminal history and the fact that he had marijuana
in his pocket. Chapman and Collier both testified that he was
not carrying a bag either before or after they entered the
abandoned house. The jury likely discounted their testimony
based on their admitted history of drug dealing. On the other
hand, discrepancies and gaps in the evidence undermined the
officers’ account: (1) Chapman’s fingerprints were not found
16                                                No. 12-1415

on any of the contraband, and someone else’s fingerprints were
on the drug packaging; (2) Officer McHale’s account of
entering the gangway was contradicted by photographic
evidence suggesting that he could not physically have done so;
and (3) neither Collier nor the unidentified woman who was in
the abandoned house are mentioned in the police reports.
    In short, here, as in Miller, the government’s case would
have been significantly less convincing if the improperly
admitted other-act evidence had been excluded. The prosecu-
tor seemed to concede as much in struggling to explain the
inconsistent verdict at sentencing. The Rule 404(b) error was
not harmless.


B. The Exclusion of Chapman’s Rehabilitation Testimony
    The district court permitted the government to introduce
Chapman’s six prior felony convictions to impeach his credibil-
ity as a witness. Chapman sought to rehabilitate himself by
explaining that he had pleaded guilty in his earlier cases
because he in fact was guilty and wanted to take responsibility
for his actions. The point of this testimony was to set up an
argument that despite his felonious history, Chapman is not
necessarily a dishonest person. Or so his counsel wanted to
argue. The government objected, and the judge sustained the
objection, precluding this line of inquiry.
    Chapman argues that this was error, and we agree. As an
initial matter, the judge seems to have misunderstood the point
of this evidence. Chapman’s argument was that he had
pleaded guilty to past charges to take responsibility for his
No. 12-1415                                                    17

actions and that his guilty pleas suggested that even though he
has a criminal record, his credibility should not be discounted,
or at least not discounted as much as it otherwise would be
without this evidence. In contrast the judge thought that
Chapman wanted to argue that because he had not contested
his earlier cases but was contesting this one, he must be
innocent. There is an important difference here: Chapman’s
actual argument was directed at his credibility as a witness; the
argument the judge thought he was making was directed at
guilt or innocence.
    Beyond this misunderstanding, the record does not clearly
reveal the basis for the judge’s ruling. At a break in the
testimony, Chapman’s counsel asked the judge to clarify her
decision to disallow the proposed rehabilitation testimony. At
this point in the transcript, the judge seems to rely on Rule 609,
which governs the admission of criminal convictions for
impeachment purposes. That rule provides, in pertinent part:
           (a) … The following rules apply to attacking
       a witness’s character for truthfulness by evidence
       of a criminal conviction:
               (1) for a crime that, in the convicting
           jurisdiction, was punishable by death or by
           imprisonment for more than one year, the
           evidence: …
                  (B) must be admitted in a criminal case
              in which the witness is a defendant, if the
              probative value of the evidence out-
              weighs its prejudicial effect to that defen-
              dant … .
18                                                               No. 12-1415

FED. R. EVID. 609(a). In other words, felony convictions are
presumptively admissible as evidence of untruthfulness if the
probative value of this evidence is not outweighed by its
prejudicial effect.2
    But nothing in Rule 609 says that this method of impeach-
ment is irrebuttable. To the contrary, the rules of evidence
specifically allow rehabilitation by introduction of other
evidence of truthfulness. Rule 608 provides that character and
reputation evidence and in some cases specific instances of
conduct may be admitted to support a witness’s truthfulness
if his credibility has been attacked.3 So to the extent that the


2
 The rule provides that certain prior felonies are presumptively admissible
to impeach a testifying defendant unless the court finds that “the probative
value of the evidence outweighs its prejudicial effect to that defendant.”
FED. R. EVID. 609(a)(1)(B). This is a higher standard than Rule 403, which
more generally gives the court discretion to exclude otherwise relevant
evidence if its probative value is substantially outweighed by its prejudicial
effect. See FED. R. EVID. 403. The district court did not expressly weigh the
probative value of the convictions against their prejudicial effect as required
by Rule 609, but Chapman does not challenge their admission, so we need
not address the issue further.

3
 Although Rule 608(b) refers to inquiries into specific instances of conduct
“on cross-examination” once a witness’s truthfulness has been challenged,
counsel can inquire into specific instances of the witness’s truthful conduct
to rehabilitate the witness on redirect examination. 4 MICHAEL H. GRAHAM,
HANDBOOK OF FEDERAL EVIDENCE § 608:4 n.12 (7th ed. 2012) (“If character
for truthfulness or untruthfulness surfaces for the first time on cross-
examination, redirect is treated as equivalent to cross-examination for the
purpose of permitting use of specific instances of conduct under
Rule 608(b).”); cf. Gov’t of V.I. v. Roldan, 612 F.2d 775, 778 n.2 (3d Cir. 1979)
                                                                   (continued...)
No. 12-1415                                                             19

judge was under the impression that Rule 609 or any other rule
categorically precluded Chapman’s proffered rehabilitation
testimony, the ruling was based on an error of law and
necessarily was an abuse of discretion. See United States v.
Smith, 674 F.3d 722, 728 (7th Cir. 2012) (“The district court
abuses its discretion when it makes an error of law … .”
(quoting United States v. Freeman, 650 F.3d 673, 678 (7th Cir.
2011))).
    The record reflects no other basis for excluding this testi-
mony. Neither the prosecutor nor the judge relied on Rule 403,
for instance, and nothing in the discussion among counsel and
the court suggests that the judge was in effect balancing the
probative value of the rehabilitation evidence against the
danger of unfair prejudice, confusion of the issues, or any other
permitted basis for excluding otherwise relevant evidence.
Accordingly, it was error to exclude Chapman’s proposed
rehabilitation testimony.
    The remaining question is whether the error was harmless.
We have already held that the Rule 404(b) error requires a new
trial, so the harmlessness question on this additional error is
superfluous. In any event, the parties have not addressed
whether the exclusion of Chapman’s rehabilitation testimony


3
 (...continued)
(upholding admission of specific instances of conduct to demonstrate
character on redirect examination, explaining: “Character evidence was
introduced for the first time on cross-examination. For the purpose of
rebuttal of this evidence, therefore, the Government's redirect examination
was the functional equivalent of the ‘cross-examination’ referred to in
rule 405(a).”).
20                                                  No. 12-1415

was prejudicial, and because the government bears the burden
of showing harmlessness, United States v. Vasquez, 635 F.3d 889,
899 (7th Cir. 2011), Chapman wins by default.


C. The Exclusion of Derrick Lewis’s Testimony
    Chapman’s last argument is that the district court’s refusal
to compel Derrick Lewis’s testimony deprived him of his Sixth
Amendment right to compulsory process. See U.S. CONST.
amend. VI (“In all criminal prosecutions, the accused shall
enjoy the right … to have compulsory process for obtaining
witnesses in his favor … .”). Chapman’s argument pits his
Sixth Amendment right to compulsory process against Lewis’s
Fifth Amendment right against self-incrimination.
    The conventional response to this clash of rights is that the
witness’s Fifth Amendment privilege trumps the defendant’s
Sixth Amendment right. See United States v. Mabrook, 301 F.3d
503, 506 (7th Cir. 2002). The analytical framework is this:
       When a potential witness indicates that he will
       likely invoke his privilege against self-incrimina-
       tion, the district court should ensure that the
       witness cannot possibly incriminate himself. If a
       witness’s testimony may make him vulnerable to
       prosecution, the trial court may allow him to
       invoke his privilege and refuse to testify.
Id.
   Thus, the witness’s testimony need only “make [the
witness] vulnerable to prosecution.” Id. This means that the
No. 12-1415                                                                21

Fifth Amendment may be invoked “where the witness has
reasonable cause to apprehend danger from a direct answer”
to the questions that may be put to him during his compelled
testimony.4 United States v. Longstreet, 567 F.3d 911, 922 (7th
Cir. 2009) (internal quotation marks omitted). Further, because
“[a] testifying witness cannot deprive the opposing party of the
right of cross-examination,” id. at 923 (internal quotation marks
omitted), the witness’s Fifth Amendment privilege must be
honored even if the danger of self-incrimination arises from
cross-examination rather than direct examination. Although
we normally review claimed constitutional errors de novo, this
particular question is subject to more deferential review for
abuse of discretion. See Mabrook, 301 F.3d at 506.


4
  Although the text of the Fifth Amendment provides that “[n]o person …
shall be compelled in any criminal case to be a witness against himself,”
U.S.CONST. amend. V (emphasis added), established doctrine assumes that
a person may invoke his Fifth Amendment privilege against self-incrimina-
tion in a variety of settings beyond his own criminal trial. As the Supreme
Court has explained:
        The Amendment not only protects the individual against
        being involuntarily called as a witness against himself in
        a criminal prosecution but also privileges him not to
        answer official questions put to him in any other proceed-
        ing, civil or criminal, formal or informal, where the
        answers may incriminate him in future criminal proceed-
        ings.
Lefkowitz v. Turley, 414 U.S. 70, 77 (1973). Where, as here, a witness’s Fifth
Amendment right against self-incrimination conflicts with the defendant’s
Sixth Amendment right to compel witnesses in his favor, this broad
understanding of the Fifth Amendment privilege effectively favors potential
defendants over actual defendants.
22                                                 No. 12-1415

   Prosecutors can resolve the tension between Fifth and Sixth
Amendment rights by granting testimonial immunity under
18 U.S.C. § 6002. Once immunity is granted, the witness may
be compelled to testify, but his testimony cannot be used
against him in his own criminal trial. 18 U.S.C. § 6002. This
mechanism rarely benefits defendants, however, because
       [a]s a matter of [Department of Justice] policy,
       18 U.S.C. § 6002 will not be used to compel the
       production of testimony or other information on
       behalf of a defendant except in extraordinary
       circumstances where the defendant plainly
       would be deprived of a fair trial without such
       testimony or other information. This policy is not
       intended to preclude compelling a defense
       witness to testify if the prosecutor believes that
       to do so is necessary to a successful prosecution.
UNITED STATES ATTORNEYS’ MANUAL ch. 9-23.214, available at
http://www.justice.gov/usao/eousa/foia_reading_room/ usam/
title9/23mcrm.htm (last visited Aug. 26, 2014) (emphases
added). In other words, it’s not enough that a defendant might
be deprived of a fair trial without the desired testimony; the
government’s policy is to grant immunity only where the
failure to do so would plainly deprive the defendant of a fair
trial.
   Some courts have assumed the power to grant immunity
themselves. See, e.g., Gov’t of V.I. v. Smith, 615 F.2d 964, 974
(3d Cir. 1980) (requiring defense-witness immunity “when it is
found that a potential defense witness can offer testimony
which is clearly exculpatory and essential to the defense case
No. 12-1415                                                    23

and when the government has no strong interest in withhold-
ing use immunity”). We have not. See United States v. Herrera-
Medina, 853 F.2d 564, 568 (7th Cir. 1988); United States v. Hooks,
848 F.2d 785, 802 (7th Cir. 1988). Nor have we assumed the
authority to order a prosecutor to grant a witness immunity.
See United States v. Burke, 425 F.3d 400, 411 (7th Cir. 2005).
   Instead, we have held that a prosecutor’s refusal to do so
may amount to a denial of due process, but only in very
limited circumstances:
       [T]he prosecutor’s power to seek or to refuse to
       seek immunity is limited by the constitutional
       right to due process of the law. Accordingly, this
       appellate court will not review a prosecutor’s
       immunization decisions in the absence of sub-
       stantial evidence showing that the prosecutor's
       actions amounted to a clear abuse of discretion
       violating the due process clause. The prosecutor
       has abused his discretion when he intends to use
       his authority to distort the judicial fact-finding
       process.
Hooks, 848 F.2d at 799 (internal quotation marks and citations
omitted); see also Burke, 425 F.3d at 411 (“A defendant’s due-
process rights are violated when the prosecutor abuses his
authority to immunize witnesses with the intention of distort-
ing the fact-finding process.”); Herrera-Medina, 853 F.2d at 568
(explaining that although a court cannot order the government
to immunize a defense witness, a court can dismiss an indict-
ment when the prosecutor’s refusal to grant immunity
amounts to a denial of due process). As far as we can tell, this
24                                                   No. 12-1415

court has never found that the failure to grant immunity to a
defense witness deprived the defendant of due process. See
Herrera-Medina, 853 F.2d at 568 (“[W]e know of no case that has
actually been dismissed on this ground.”). Chapman has not
argued that the government abused its authority and refused
to immunize Lewis to distort the fact-finding process.
    We agree with the district court that Lewis’s invocation of
the privilege against self-incrimination had a good-faith basis.
If the judge had compelled Lewis to testify, the prosecutor
almost certainly would have asked about his use of the
nickname “D.C.” and the precise nature of his relationship
with Collier, who had already testified that she was at the
scene talking to Lewis about dealing drugs for him. More
generally, the prosecutor likely would have cross-examined
him about his history of dealing drugs. So even if Chapman’s
direct examination was narrowly limited, the government’s
probable cross-examination of Lewis could “make him vulner-
able to prosecution.” Mabrook, 301 F.3d at 506. The district
court properly accepted Lewis’s invocation of the Fifth
Amendment and refused to compel him to testify.
   We caution, however, that this is not the end of the story.
Whether a witness may invoke the privilege against self-
incrimination depends on the circumstances that the witness
faces, and Lewis’s circumstances may have changed since the
time of the first trial. On retrial the district court may need to
assess Lewis’s invocation of the Fifth Amendment anew.
No. 12-1415                                                             25

                           III. Conclusion
    For the foregoing reasons, we VACATE Chapman’s convic-
tion and REMAND for a new trial.5




5
  Chapman also challenged his sentence, arguing that the district court
failed to adequately address his principal arguments in mitigation. Our
decision to vacate and remand for a new trial moots the challenge to the
sentence. Also moot is Chapman’s Motion for Disclosure of certain emails
between the district judge and a deputy marshal or his wife. On July 21,
2014, the judge issued an order recusing herself from further participation
in this case, and in any event, under Circuit Rule 36, a case must be
reassigned whenever there is a remand for retrial.
