                              In the

    United States Court of Appeals
                For the Seventh Circuit

Nos. 13-3343, 13-3346 & 13-3347

ROBERT LEE STINSON,
                                                  Plaintiff-Appellee,

                                v.

JAMES GAUGER, LOWELL T. JOHNSON,
and RAYMOND RAWSON,
                                            Defendants-Appellants.


           Appeals from the United States District Court
              for the Eastern District of Wisconsin.
             No. 09-C-1033 — C.N. Clevert, Jr., Judge.



      ARGUED JUNE 6, 2014 — DECIDED AUGUST 25, 2015



   Before BAUER, MANION, and SYKES, Circuit Judges.
    SYKES, Circuit Judge. Robert Lee Stinson spent 23 years in
prison for a murder he did not commit. He was exonerated by
DNA evidence and now sues the lead detective and two
forensic odontologists who investigated the murder and later
testified at trial. The odontologists were the key witnesses for
2                             Nos. 13-3343, 13-3346 & 13-3347

the prosecution. They testified that bite marks on the victim’s
body matched Stinson’s dentition. In this suit for damages, see
42 U.S.C. § 1983, Stinson alleges that the odontologists
fabricated their opinions, the detective put them up to it, and
all three defendants suppressed evidence of the fabrication, all
in violation of his right to due process of law.
    The case comes to us on appeal from the district court’s
denial of the defendants’ claim of absolute or qualified
immunity from suit. We agree that absolute immunity does not
apply. Stinson has sued the defendants primarily for their
investigative misconduct, not their testimony at trial. But the
defendants remain protected by qualified immunity, which is
lost only if Stinson presents evidence showing that they
violated a clearly established constitutional right. He has not
done so. Stinson’s evidence, accepted as true, shows at most
that the odontologists were negligent; it does not support his
claim that they fabricated their opinions. And an error in
forensic analysis—even a glaring error—is not actionable as a
violation of due process. Finally, Stinson’s evidence-
suppression claim is wholly dependent on the allegation of
fabrication, which is unsupported by the record. Accordingly,
we reverse and remand with instructions to enter judgment for
the defendants.


                        I. Background
   The immunity issue was raised at the summary-judgment
stage, so our factual account of the case comes from the
evidence submitted in support of and opposition to the
defendants’ Rule 56 motion, see FED. R. CIV. P. 56, construed in
Nos. 13-3343, 13-3346 & 13-3347                                3

Stinson’s favor, Locke v. Haessig, 788 F.3d 662, 666–67 (7th Cir.
2015).
    At about 7 a.m. on November 3, 1984, Milwaukee police
were dispatched to the scene of a homicide at 2650 N. 7th
Street. In the rear yard at that address, they found the body of
Ione Cychosz; she had been brutally raped and murdered. The
most promising physical evidence was a set of bite marks left
on Cychosz’s body, so the Milwaukee County Medical
Examiner asked Dr. Lowell Johnson to assist on the case.
Dr. Johnson was a professor of dentistry and oral surgery at
Marquette University, a forensic odontologist, and a diplomate
of the American Board of Forensic Odontology. At the Medical
Examiner’s request, Dr. Johnson examined the bite marks on
Cychosz’s body and made rubber impressions of them.
    About two days after the murder, Milwaukee homicide
detective James Gauger and his partner, Tom Jackelen,
assumed responsibility for the investigation. They started by
reviewing the work other officers had done to that point and
meeting with Dr. Johnson, who described the killer’s teeth and
showed them a preliminary sketch. No police reports
memorialize this meeting and the parties dispute what was
said, but according to Stinson’s version of events, Dr. Johnson
informed the detectives of his working hypothesis: the killer
had one twisted tooth and was missing the upper right lateral
incisor (the tooth just to the right of the two front teeth).
    Armed with this information, the two detectives began
interviewing people who lived near the scene of the crime.
Stinson’s house was immediately to the north of the yard
where the body was found. Gauger already knew Stinson. Two
4                              Nos. 13-3343, 13-3346 & 13-3347

years earlier, Gauger had tried and failed to prove that Stinson
was responsible for the murder of a man named Ricky
Johnson. The Johnson homicide was never solved, even though
a witness identified Stinson and two others as having been
involved. To this day, Gauger believes that Stinson was
responsible for Ricky Johnson’s murder.
    Gauger and Jackelen went to Stinson’s home and initially
spoke with his mother and brother. Gauger then separately
interviewed Stinson’s brother while Jackelen interviewed
Stinson. When they finished, the detectives compared notes
outside the Stinson home. Jackelen told Gauger, “We have
him.” Gauger asked Jackelen what he meant, and the two
detectives then returned to the house to talk with Stinson
again. Jackelen’s plan was to say something that would make
Stinson laugh so they could see his teeth. He did so, and
Gauger and Jackelen saw that Stinson was missing his right
front tooth (his right central incisor) and had another tooth that
was badly damaged. That did not quite match the description
Dr. Johnson had given: Stinson’s missing tooth was the one just
next to the tooth that the odontologist said would be missing.
Nonetheless, the detectives thought they’d found their man.
    The detectives met with District Attorney E. Michael
McCann and Assistant District Attorney Daniel Blinka to
report the status of the investigation. Blinka summoned
Dr. Johnson to the meeting, and Johnson said he would need
to personally examine Stinson to determine whether his teeth
matched the bite marks on Cychosz’s body. Blinka did not
think they had enough evidence for a warrant compelling
Stinson to submit to a dental examination, so he decided to
Nos. 13-3343, 13-3346 & 13-3347                              5

open a John Doe proceeding—a unique procedure authorized
by Wisconsin law that allows district attorneys to (among other
things) subpoena witnesses to appear and give evidence before
a judge in order to determine whether probable cause exists to
charge someone with a crime. See WIS. STAT. § 968.26. On
Blinka’s petition a Milwaukee County Circuit Judge opened a
John Doe proceeding to investigate the Cychosz murder.
    Stinson was subpoenaed and on December 3 submitted to
examination at a hearing before the John Doe judge.
Dr. Johnson evaluated him on the spot and stated that his teeth
were consistent with the bite marks on Cychosz’s body. The
judge overseeing the hearing ordered Stinson to submit to a
more thorough dental examination, including the production
of molds, wax impressions, and photographs of his teeth.
Dr. Johnson’s conclusion at the end of this more detailed
analysis was the same: Stinson’s teeth matched the bite marks
on the victim.
    Blinka was not quite convinced and wanted a second
opinion. So Johnson and Gauger flew to Las Vegas to meet
with Dr. Raymond Rawson, a forensic odontologist on the staff
of the Clark County Coroner’s Office in Nevada. Dr. Rawson
was also an adjunct professor of biology at the University of
Las Vegas and, like Dr. Johnson, a diplomate of the American
Board of Forensic Odontology. Dr. Rawson had not been
involved in the case to that point but agreed to examine the
evidence and possibly render an opinion. After a brief look at
the evidence in Gauger’s hotel room, Dr. Rawson agreed with
Dr. Johnson’s opinion that Stinson’s dentition matched the bite
marks on Cychosz’s body.
6                             Nos. 13-3343, 13-3346 & 13-3347

    This corroboration satisfied Blinka. Stinson was arrested
and charged with Cychosz’s murder. The bite-mark evidence
was the centerpiece of the prosecution, and Drs. Johnson and
Rawson were the star witnesses. Before trial the prosecutor
gave all the bite-mark evidence to Stinson’s counsel and also
provided a list of forensic odontologists available to the
defense to independently review the bite-mark evidence and
render an opinion. Indeed, Stinson’s counsel hired one of these
odontologists, but to no avail: The expert agreed with
Drs. Johnson and Rawson that the bite-mark evidence
implicated Stinson, so the defense attorney did not call him to
testify at trial. On December 12, 1985, a jury found Stinson
guilty. He was sentenced to life in prison.
    Twenty-three years later, Stinson was exonerated with help
from the Wisconsin Innocence Project after it was shown that
DNA evidence collected from Cychosz’s body excluded
Stinson. The Innocence Project also enlisted a new panel of
odontologists who reexamined the bite-mark evidence and
determined that it too excluded Stinson. On January 30, 2009,
the judgment was vacated and Stinson was released from
prison. Not long after that, state experts matched the DNA
evidence recovered from Cychosz’s body with a DNA sample
from Moses Price, who thereafter confessed to the murder. The
charges against Stinson were dismissed.
   In 2010 Gauger copyrighted a memoir entitled The Memo
Book, recounting his life as a Milwaukee police officer and
detective. In it he described the Ricky Johnson and Ione
Cychosz homicide investigations and revealed for the first time
that he and Jackelen had met with Dr. Johnson before they
Nos. 13-3343, 13-3346 & 13-3347                                 7

began canvassing the neighborhood around the Cychosz
murder scene.
    After his release from prison, Stinson filed this civil-rights
lawsuit against Gauger and Drs. Johnson and Rawson alleging
that they conspired to frame him for the Cychosz murder. He
retained a new expert odontologist, Dr. C. Michael Bowers,
who agreed with the Innocence Project panel that the bite-mark
evidence clearly excluded Stinson. Dr. Bowers and the panel
also agreed that the forensic evaluations by Drs. Johnson and
Rawson fell far below any accepted standard of forensic
odontology. In Dr. Bowers’s view, Drs. Johnson and Rawson
went to great lengths to fit the bite-mark evidence to Stinson’s
dentition. Relying heavily on Dr. Bowers’s opinion, Stinson
alleges in his suit that Drs. Johnson and Rawson fabricated
evidence against him (namely, their expert opinions), that
Gauger solicited or conspired with them to do so, and that all
three defendants covered up the fabrication. The fabrication
claim rests on Whitlock v. Brueggemann, 682 F.3d 567 (7th Cir.
2012); the cover-up claim alleges that the defendants violated
the due-process disclosure duty announced in Brady v.
Maryland, 373 U.S. 83 (1963).
    The defendants moved for summary judgment based on
absolute immunity, or alternatively, qualified immunity from
suit. The district judge rejected the claim of absolute immunity
because Stinson’s fabrication claim focused on misconduct that
occurred during the investigation, before the case was charged,
and not on the defendants’ role as witnesses at trial. The judge
also rejected the claim of qualified immunity, concluding that
Dr. Bowers’s affidavit, along with Gauger’s belief that Stinson
8                                Nos. 13-3343, 13-3346 & 13-3347

was responsible for the still-unsolved Ricky Johnson homicide,
supported Stinson’s claim that the defendants conspired to
frame him. The judge accordingly denied summary judgment.
All three defendants appealed.


                          II. Discussion
A. Appellate Jurisdiction
    An order denying summary judgment normally lacks the
finality required for appellate jurisdiction under 28 U.S.C.
§ 1291, Gutierrez v. Kermon, 722 F.3d 1003, 1009 (7th Cir. 2013),
but orders denying claims of immunity from suit are an
exception, Mitchell v. Forsyth, 472 U.S. 511, 524–30 (1985). These
orders are effectively final with respect to the defendant’s right
to avoid the burdens of litigation and trial, so appellate
jurisdiction arises under § 1291 pursuant to the collateral-order
doctrine, which permits immediate appeal of a “small class” of
orders that “finally determine claims of right separable from,
and collateral to, rights asserted in the action, too important to
be denied review and too independent of the cause itself to
require that appellate consideration be deferred until the whole
case is adjudicated.” Id. at 524–25 (quoting Cohen v. Beneficial
Indus. Loan Corp., 337 U.S. 541, 546 (1949)).
    This principle is subject to an important limitation,
however. In Johnson v. Jones, the Supreme Court explained that
“a defendant, entitled to invoke a qualified immunity defense,
may not appeal a district court’s summary judgment order
insofar as that order determines whether or not the pretrial
record sets forth a ‘genuine’ issue of fact for trial.” 515 U.S. 304,
Nos. 13-3343, 13-3346 & 13-3347                                   9

319 (1995). The plaintiff in Johnson alleged that five police
officers used excessive force during an arrest, beating him so
severely that he required hospitalization for broken ribs. Id. at
307. Three of the officers moved for summary judgment,
asserting qualified immunity and arguing that the plaintiff had
no evidence that any of them were involved in the beating. Id.
at 307–08. Relying on the plaintiff’s statement that some
unidentified officers beat him and the officers’ deposition
admissions that they had been present at the scene, the district
court determined that the plaintiff had raised a genuine factual
dispute about whether these particular officers participated in
the beating and on that basis denied the qualified-immunity
motion. Id. The officers appealed, arguing that the summary-
judgment record did not support the plaintiff’s version of the
facts. Id. at 308. Because the district court’s ruling entailed only
a determination of the sufficiency of the evidence—a purely
factual question—the Supreme Court held that it was not
immediately appealable. See id. at 313–17.
    At first blush Johnson might be seen as foreclosing this
appeal, but the Court’s decision must be read in light of its
later decisions in Scott v. Harris, 550 U.S. 372 (2007), and
Plumhoff v. Rickard, 134 S. Ct. 2012 (2014). At issue in Scott was
whether a police officer used excessive force when he rammed
the plaintiff’s fleeing car during a high-speed chase, a question
that turned in part on whether a reasonable officer would have
believed that the plaintiff’s flight posed a danger to the public.
The district court denied the officer’s claim of qualified
immunity, holding that a jury could side with the plaintiff and
find that a reasonable officer would not have believed that the
plaintiff’s flight posed a threat to the safety of others. See
10                               Nos. 13-3343, 13-3346 & 13-3347

Harris v. Coweta County, No. CIVA 3:01CV148 WBH, 2003 WL
25419527, at *5 (N.D. Ga. Sept. 25, 2003). The Eleventh Circuit
affirmed, Harris v. Coweta County, 433 F.3d 807, 816 (11th Cir.
2005), but the Supreme Court reversed, holding that the
plaintiff’s story was “blatantly contradicted by the record,”
which included a video recording of the chase. 550 U.S. at 380.
    The qualified-immunity question in Scott therefore turned
on a pure question of law: “whether [the officer’s] actions were
objectively reasonable” under the Fourth Amendment in light
of the danger created by the plaintiff’s high-speed flight, as
captured on the video recording. Id. at 381. The Court had
“little difficulty” concluding that “it was reasonable for [the
officer] to take the action that he did.” Id. at 384.
    The Court’s opinion in Scott does not mention Johnson, but
the decision inescapably implies that Johnson should not be
read too expansively. The Court made this point explicit in
Plumhoff, which specifically addressed the limits of Johnson’s
no-jurisdiction holding in light of Scott. Plumhoff, like Scott,
involved a high-speed police chase: The claim in Plumhoff was
that police used excessive force by shooting at a fleeing car.
134 S. Ct. at 2017–18. Like the district court in Scott, the district
court in Plumhoff found a genuine factual dispute about the
degree of danger posed by the driver and thus rejected the
officers’ claim of qualified immunity. Applying Johnson, the
Sixth Circuit initially determined that it lacked jurisdiction to
hear the officers’ appeal, but the court later reversed course
and affirmed the district court on the merits. Id.
   The Supreme Court reversed. Addressing the question of
appellate jurisdiction, the Court explained that unlike the
Nos. 13-3343, 13-3346 & 13-3347                                  11

officers in Johnson, the officers in Plumhoff weren’t contesting a
purely factual issue; instead, they raised a question of law. Id.
at 2019. They did not claim, for example, “that other officers
were responsible for [the] shooting … ; rather, they
contend[ed] that their conduct did not violate the Fourth
Amendment and, in any event, did not violate clearly
established law.” Id. In other words, they acknowledged for
purposes of their summary-judgment motion that they had
fired shots at the fleeing car, but they argued that the shooting
was a reasonable response to the danger the high-speed chase
created, or in the alternative, that a reasonable officer would
not have known that the shooting was unjustified in light of
that danger.
    The Supreme Court explained that these were “legal
issues … quite different from any purely factual issues that the
trial court might confront if the case were tried.” Id. As such,
the Court held that Johnson did not apply. Id. The Court went
on to conclude that the case was indistinguishable from Scott,
and the record unequivocally showed that the driver posed a
serious risk to public safety, justifying the officers’ actions. See
id. at 2021–22. Alternatively, the Court held that the officers
were entitled to qualified immunity. Id. at 2024.
    Scott and Plumhoff make it clear that Johnson should not be
understood as establishing a categorical bar to immediate
appellate review of an order denying immunity whenever the
lower court has determined that facts are in dispute. The
jurisdictional inquiry requires a more nuanced assessment of
the specific immunity claim asserted in the case to determine
whether the appeal raises a question of law, as in Plumhoff and
12                              Nos. 13-3343, 13-3346 & 13-3347

Scott, or merely a dispute about historical facts, as in Johnson.
Here, the defendants have accepted Stinson’s version of the
historical facts for present purposes; they argue that those
facts, even with inferences drawn in Stinson’s favor, do not
amount to a violation of a clearly established constitutional
right. That is the legal question at the heart of a qualified-
immunity claim. The district court’s order qualifies for
immediate appeal.


B. Absolute Immunity
    Our jurisdiction secure, we begin with the odontologists’
claim of absolute immunity. Witnesses have absolute immunity
from suit on claims stemming from their testimony at trial and,
as a corollary, from their preparation to testify at trial. See
Rehberg v. Paulk, 132 S. Ct. 1497, 1506–07 (2012); Briscoe v.
LaHue, 460 U.S. 325, 326 (1983). Even if Johnson and Rawson
testified falsely at Stinson’s trial, that testimony can’t be the
basis of a civil suit against them. The principle underlying this
expansive immunity is that without it, witnesses might be
reticent to testify or might hedge their testimony to reduce the
chance of a retaliatory or harassing lawsuit against them. See
Rehberg, 132 S. Ct. at 1505. Moreover, civil liability is not
considered necessary to deter false testimony; the threat of
criminal prosecution for perjury is a sufficient deterrent. See id.
    Drs. Johnson and Rawson argue that all of Stinson’s claims
arise from their trial testimony or its preparation. Not so.
Stinson’s claims focus primarily on actions the two
odontologists took while investigating the Cychosz murder.
Nos. 13-3343, 13-3346 & 13-3347                               13

That’s a key distinction in the context of absolute immunity. In
Buckley v. Fitzsimmons, or Buckley III as it’s known in this
circuit, the Supreme Court held that a prosecutor’s absolute
immunity covers allegations of misconduct committed during
trial and in preparing for trial, but not misconduct committed
while investigating the case. 509 U.S. 259, 273 (1993). “There is
a difference,” the Court said, “between the advocate’s role in
evaluating evidence and interviewing witnesses as he prepares
for trial, on the one hand, and the detective’s role in searching
for the clues and corroboration that might give him probable
cause to recommend that a suspect be arrested, on the other
hand.” Id. A prosecutor who participates in a criminal
investigation performs essentially the same function as a
detective, so as a useful shorthand, the Court held that a
prosecutor’s conduct before probable cause exists ordinarily
should be classified as investigative work rather than trial
preparation, and as such is not covered by absolute immunity.
See id. at 274.
    Even after probable cause exists, a prosecutor might
continue acting as an investigator, in which case absolute
immunity remains inapplicable. See id. at 274 n.5. Whether this
investigative work is later used at trial is irrelevant: “A
prosecutor may not shield his investigative work with the aegis
of absolute immunity merely because, after a suspect is
eventually arrested, indicted, and tried, that work may be
retrospectively described as ‘preparation’ for a possible trial.”
Id. at 276.
   If a prosecutor isn’t absolutely immune for misconduct
occurring during an investigation, before probable cause exists,
14                            Nos. 13-3343, 13-3346 & 13-3347

then it’s hard to see how a forensic expert working with the
prosecutor to develop probable cause would be protected by
absolute immunity. The immunities for prosecutors and
witnesses derive from the same common-law immunity that
covers all essential participants in a trial, and both exist to
protect the truth-seeking function of trials by allowing
participants to speak and act freely without threat of civil
liability. See Briscoe, 460 U.S. at 334–36 & n.15.
    Indeed, the Supreme Court recently noted, if only in
passing, that the distinction drawn in Buckley III—between
alleged misconduct during trial and trial preparation (for
which a prosecutor is absolutely immune) and alleged
misconduct during an investigation (for which a prosecutor
has only qualified immunity)—applies to witnesses as well. In
Rehberg the Court held that a witness is entitled to absolute
immunity for his testimony before a grand jury and for
preparing grand-jury testimony. 132 S. Ct. at 1507. The Court
was careful to note, however, that absolute immunity does not
extend “to all activity that a witness conducts outside of the
grand jury room. For example, we have accorded only
qualified immunity to law enforcement officials who falsify
affidavits … and fabricate evidence concerning an unsolved
crime.” Id. at 1507 n.1 (citing, among other cases, Buckley III,
509 U.S. at 272–76).
    Here, Stinson accuses the odontologists of fabricating their
opinions during the investigative phase of the Cychosz case,
before probable cause existed. In light of Rehberg and the
principles outlined in Buckley III, absolute immunity does not
apply to this alleged misconduct.
Nos. 13-3343, 13-3346 & 13-3347                              15

     Finally, we note that absolute immunity does not protect
a witness who violates a Brady obligation by suppressing
material exculpatory information concerning the investigation
of a crime. See Manning v. Miller, 355 F.3d 1028, 1033 (7th Cir.
2004) (holding that absolute immunity did not apply to
witnesses accused of concealing their fabrication of evidence);
Ienco v. City of Chicago, 286 F.3d 994, 1000 (7th Cir. 2002)
(“Neither the withholding of exculpatory information nor the
initiation of constitutionally infirm criminal proceedings is
protected by absolute immunity.”).


C. Qualified Immunity
    Although not absolutely immune from suit, the defendants
remain protected by qualified immunity unless Stinson has
evidence showing that their conduct violated a constitutional
right and the right was clearly established at the time of their
actions. See Pearson v. Callahan, 555 U.S. 223, 243–44 (2009).
Relying on Whitlock, he alleges that the odontologists violated
his Fourteenth Amendment right to due process by fabricating
their bite-mark opinions and that all three defendants took part
in a conspiracy to frame him with this fabricated evidence. He
also alleges that the defendants engaged in a cover-up by
suppressing evidence of the fabrication in violation of Brady.


   1. Fabrication of Evidence
   The core of Stinson’s case is his contention that
Drs. Johnson and Rawson falsified their expert opinions and
that Gauger solicited or conspired with them to do so. Recent
16                               Nos. 13-3343, 13-3346 & 13-3347

cases in this circuit hold that a prosecutor who fabricates
evidence against a suspect and later uses that evidence to
convict him violates due process, and this due-process right
was clearly established by at least the early 1980s. See Fields v.
Wharrie (“Fields II”), 740 F.3d 1107, 1114 (7th Cir. 2014);
Whitlock, 682 F.3d at 585–86. The constitutional violation occurs
when the evidence is fabricated, not when the fabricated
evidence is later introduced at trial—a crucial distinction
because the prosecutor would have absolute immunity for any
constitutional violation committed during the trial. See, e.g.,
Fields v. Wharrie (“Fields I”), 672 F.3d 505, 517–18 (7th Cir. 2012);
Buckley v. Fitzsimmons (“Buckley IV”), 20 F.3d 789, 794–95 (7th
Cir. 1994).
    It’s not entirely clear that the same reasoning applies to
police officers and expert witnesses who are alleged to have
fabricated evidence during an investigation. Unlike
prosecutors, police investigators face liability for failing to
disclose their own fabrication of evidence. See, e.g., Manning,
355 F.3d at 1034. That’s because immunity doesn’t protect an
officer who fails to disclose material exculpatory evidence as
required by Brady, see id. at 1033, even though a prosecutor
who did the same thing would have absolute immunity for the
suppression, see Fields I, 672 F.3d at 514.
    Moreover, a line of cases in this circuit has squarely held
that a police officer’s fabrication of evidence (as distinct from
his suppression of material exculpatory evidence) is not
actionable as a violation of due process as long as state law
provides an adequate remedy for the fabrication—usually in
the form of a malicious-prosecution tort action. See, e.g.,
Nos. 13-3343, 13-3346 & 13-3347                                  17

McCann v. Mangialardi, 337 F.3d 782, 786 (7th Cir. 2003). Under
these cases due process is satisfied as long as the state permits
a suit against the culpable officer after the fact. See id.; Newsome
v. McCabe, 256 F.3d 747, 750–51 (7th Cir. 2001). Whitlock did not
address this line of cases. If they remain good law, then the
due-process claim against prosecutors recognized in Whitlock
and applied in Fields II might not be available against police
officers (and other members of the investigative team, like
forensic experts) unless state law lacks an adequate tort
remedy for the fabrication of evidence.
    We don’t need to resolve this question, however, because
Stinson’s claims fail even assuming Whitlock and Fields II apply
to state actors other than prosecutors. See Petty, 754 F.3d at
421–22 (declining to address the relationship between McCann
and Whitlock because plaintiff’s claims failed even if Whitlock
applied to police officers). The due-process liability recognized
in Whitlock arises only in a narrow category of cases involving
evidence fabrication; the panel took care to distinguish
constitutionally actionable fabrication claims from other forms
of official wrongdoing—such as “[c]oercively interrogating
witnesses, paying witnesses for testimony, and
witness-shopping.” 682 F.3d at 584. The latter “may be
deplorable, and … may contribute to wrongful convictions, but
they do not necessarily add up to a constitutional violation
even when their fruits are introduced at trial.” Id.
    Whitlock thus distinguished this court’s earlier decision in
Buckley IV, which rejected a due-process claim based on
allegations that investigators coerced and solicited false
testimony. Buckley involved a prosecutor who had been told by
18                              Nos. 13-3343, 13-3346 & 13-3347

three different experts that a bootprint left at the scene of the
crime could not reliably implicate Buckley, but sought a fourth
opinion from an expert who had a reputation for producing
scientifically unreliable opinion testimony. 20 F.3d at 796. She
told the prosecutor and investigators “that no one but Buckley
could have left the bootprint on the door—and that she could
identify the wearer of a shoe with certainty even if she had
only prints made with different shoes.” Id. We explained in
Buckley IV that “[n]either shopping for a favorable witness nor
hiring a practitioner of junk science is actionable” as a
constitutional violation; a due-process violation occurs, if at all,
only when the testimony is offered at trial without compliance
with Brady. Id. at 796–97.
    Whitlock did not disagree with Buckley IV on this point.
Instead the panel distinguished shopping for unreliable experts
(among other wrongful conduct at issue in Buckley IV) from the
evidence falsification at issue in Whitlock, which involved
feeding witnesses details of crimes that they couldn’t have
known. See Whitlock, 682 F.3d at 572, 584. Why the distinction?
Because “[e]vidence collected with the[] kind[] of suspect
techniques [at issue in Buckley IV], unlike falsified evidence and
perjured testimony, may turn out to be true.” Id. at 584. Sorting
out reliable and unreliable evidence is an ordinary matter for
trial, through the crucible of the adversary process, so the use
of these suspect techniques doesn’t violate due process unless
the evidence is introduced at trial without adequate
safeguards, such as disclosure of all material exculpatory
evidence as required by Brady. Subsequent cases have
confirmed that the due-process cause of action recognized in
Whitlock is factually limited to cases involving evidence
Nos. 13-3343, 13-3346 & 13-3347                                 19

fabrication. See Petty, 754 F.3d at 422–23; see also Fields II,
740 F.3d at 1112.
    Although Stinson tries to situate his case in this category,
the record on summary judgment, construed generously in his
favor, doesn’t come close to showing that Drs. Johnson and
Rawson fabricated their expert opinions. The district judge
thought a jury could find fabrication based on Dr. Bowers’s
opinion that “Johnson’s and Rawson’s conclusions were far
afield of what a reasonable forensic odontologist would have
concluded.” This view reflects an incorrect understanding of
the fabrication claim recognized in Whitlock. Nothing in
Whitlock or Fields II suggests that an inference of fabrication can
be drawn from an expert’s opinion that another expert
behaved unreasonably under prevailing standards in the field.
Arriving at an unreasonable expert opinion may suggest
negligence, perhaps even gross negligence, but it does not
amount to the intentional fabrication of evidence. A mistake in
forensic analysis—even an egregious mistake—is grievous
given the stakes in this context, but an expert who renders a
mistaken opinion is protected by qualified immunity.
Fabricated opinion evidence, for which the expert might not
have qualified immunity, must be both wrong and known to be
wrong by the expert. See Fields II, 740 F.3d at 1110.
    Stinson places special emphasis on the discrepancy between
Dr. Johnson’s early hypothesis—that the murderer was missing
the right lateral incisor—and his ultimate opinion that
Stinson’s dentition matched the bite marks on Cychosz’s body.
(Recall that Stinson was missing his right central incisor, the
tooth just next to the right lateral incisor.) This discrepancy
20                             Nos. 13-3343, 13-3346 & 13-3347

suggests that forensic odontology is not very precise (raising
legitimate questions about its reliability), but it’s not evidence
that Dr. Johnson knew his opinion was false—i.e., that it was a
lie.
    We acknowledge that it’s not easy to prove that an expert
knowingly falsified an opinion. We also recognize that the first
step toward proving that an expert was intentionally lying is
proving that his opinion was wrong. But to conclude that an
expert fabricated his opinion solely because it was
wrong—even grossly wrong—would collapse the essential
distinction between mistaken opinions (for which there is
immunity) and fabricated opinions (for which there is not).
Stinson’s fabrication claim is based entirely on the opinions of
new experts that Drs. Johnson and Rawson were terribly
wrong about the bite-mark evidence and that they used
unreliable methods falling far below the standards of their
profession. We do not second-guess this new opinion evidence,
but it demonstrates at most that the odontologists acted
unreasonably, not that they fabricated their opinions. Stinson
has nothing else to support his evidence-fabrication claim.
   The related claim against Gauger is entirely dependent on
the viability of the evidence-fabrication claim against the
odontologists. Stinson contends that the detective solicited or
conspired with Drs. Johnson and Rawson to falsify their
opinions, or at least failed to intervene to prevent them from
doing so. Because no reasonable jury could find that the
odontologists violated Stinson’s due-process rights by
fabricating their opinions, Gauger too is entitled to qualified
immunity on this claim.
Nos. 13-3343, 13-3346 & 13-3347                                    21



   2. Suppression of Evidence
    Stinson also claims that the defendants suppressed
evidence in violation of the due-process disclosure duty
announced in Brady v. Maryland, 373 U.S. 150 (1972), and
expanded in Giglio v. United States, 405 U.S. 150 (1972). The
duty to disclose material exculpatory and impeachment
evidence extends to prosecutors and “others acting on the
government’s behalf in the case.” Kyles v. Whitley, 514 U.S. 419,
437 (1995). Thus, police officers who conceal exculpatory
evidence, or who fabricate evidence and fail to disclose the
fabrication, cannot claim the protection of qualified immunity.
See, e.g., Newsome, 256 F.3d at 752–53; Jones v. City of Chicago,
856 F.2d 985, 994 (7th Cir. 1988). We’ve suggested before that
the same reasoning applies in cases involving forensic experts
who work with the police on criminal investigations. See, e.g.,
Jones, 856 F.2d at 993 (upholding a jury verdict against a lab
technician who manipulated and concealed exculpatory
evidence). We need not decide whether it was clearly
established in 1984, when these events occurred, that forensic
experts working with the police have a duty to disclose
material exculpatory evidence; nothing in the record shows
that the duty was violated in Stinson’s case.
     The Brady rule is not violated by the presentation of flawed
expert testimony at trial. See, e.g., Sornberger v. City of Knoxville,
Ill., 434 F.3d 1006, 1029 (7th Cir. 2006); Buie v. McAdory,
341 F.3d 623, 625–26 (7th Cir. 2003). Faulty expert testimony is
exposed through the adversary process; the Brady requirement
simply ensures that the defense has all material exculpatory
22                             Nos. 13-3343, 13-3346 & 13-3347

evidence for use during cross-examination. Here, the
prosecutor disclosed all the bite-mark evidence to the defense
and even provided a list of forensic odontologists to assist
Stinson’s counsel in preparing to contest Dr. Johnson’s and
Dr. Rawson’s opinions. Far from exposing flaws in their
analysis, Stinson’s forensic expert agreed that they had correctly
evaluated the bite-mark evidence and that it inculpated
Stinson. So Stinson’s own expert missed the errors later
identified by the Innocence Project and Dr. Bowers.
    What’s left is Stinson’s allegation that Dr. Johnson failed to
disclose that he changed his mind about which tooth the killer
was missing. But the prosecution turned over Dr. Johnson’s
initial sketch to the defense, and the inconsistency between it
and his subsequent opinion was just as evident then as it is
today. See Carvajal v. Dominguez, 542 F.3d 561, 567 (7th Cir.
2008) (“There was nothing preventing Carvajal from
discovering and drawing out this discrepancy between the
officers’ stories during the suppression hearing. Suppression
does not occur when the defendant could have discovered it
himself through ‘reasonable diligence.’” (quoting Ienco v.
Angarone, 429 F.3d 680, 683 (7th Cir. 2005)). If the discrepancy
was relevant in assessing the quality or accuracy of
Dr. Johnson’s ultimate opinion, then Stinson and his expert
could have seized on the point at the time.
    We have difficulty discerning what other evidence Stinson
thinks was concealed. He hasn’t pointed to any material
evidence that has recently come to light but wasn’t disclosed
in time for his trial. He points to Gauger’s memoir, which was
copyrighted in 2010, but the material information in The Memo
Nos. 13-3343, 13-3346 & 13-3347                              23

Book—such as Gauger’s belief that Stinson was responsible for
Ricky Johnson’s murder—was known at the time of trial. The
only new fact revealed in The Memo Book was that Gauger and
Jackelen met with Dr. Johnson prior to canvassing the
neighborhood where the Cychosz murder occurred. The mere
fact of that meeting is not materially exculpatory.


   3. Remaining Claims Against the Odontologists
    Stinson’s remaining claims against Drs. Johnson and
Rawson are wholly dependent on his primary contention that
they fabricated their opinions and suppressed evidence of the
fabrication. For example, Stinson alleges that the odontologists
are liable for conspiracy, but a defendant cannot be liable “for
conspiring to commit an act that he may perform with
impunity.” House v. Belford, 956 F.2d 711, 720 (7th Cir. 1992).
For the same reason, Stinson’s claim against the odontogists for
failure to intervene also fails.


                       III. Conclusion
    For the foregoing reasons, the defendants are not protected
by absolute immunity, but they are entitled to qualified
immunity. Accordingly, we REVERSE the judgment of the
district court and REMAND with instructions to enter judgment
in favor of the defendants.
