Court Opinion

ID: 9395605
Source: CourtListenerOpinion
Date Created: 2023-05-18 15:06:13.135214+00
Date Added: 2024-06-11T17:19:09.878669
License: Public Domain

2023 IL 127241

                                         IN THE
                                SUPREME COURT
                                             OF
                          THE STATE OF ILLINOIS

                                    (Docket No. 127241)

                 THE PEOPLE OF THE STATE OF ILLINOIS, Appellant,
                            v. JOHN PRANTE, Appellee.

                                Opinion filed May 18, 2023.

        JUSTICE CUNNINGHAM delivered the judgment of the court, with opinion.

        Chief Justice Theis and Justices Neville, Overstreet, and Holder White
     concurred in the judgment and opinion.

        Justices Rochford and O’Brien took no part in the decision.

                                         OPINION

¶1       Petitioner John Prante filed a motion in the circuit court of Madison County
     seeking leave to file a successive postconviction petition challenging his conviction
     for murder. In his motion and accompanying petition, Prante asserted that recent
     scientific studies had fully discredited forensic bite mark opinion testimony that
     was introduced by the State at trial. Prante raised a claim of actual innocence, a
     separate due process claim, and three additional claims. The circuit court denied
     Prante leave to file all claims.

¶2        On appeal, the appellate court reversed the judgment of the circuit court denying
     Prante leave to file his due process claim and affirmed the judgment of the circuit
     court denying Prante leave to file his claim of actual innocence. The appellate court
     did not address Prante’s remaining claims. 2021 IL App (5th) 200074. For the
     reasons that follow, we reverse the judgment of the appellate court allowing Prante
     to file his due process claim and affirm the judgment of the appellate court denying
     Prante leave to file his claim of actual innocence. We remand the cause to the
     appellate court to address Prante’s remaining claims.

¶3                                    BACKGROUND

¶4      Following a jury trial in the summer of 1983, Prante was found guilty of the
     murder of 22-year-old Karla Brown. Evidence at trial established the following.

¶5       On June 20, 1978, Brown and her fiancé, Mark Fair, spent the day moving into
     their newly purchased home in Wood River, Illinois. Friends of the couple helped
     with the move and stayed into the evening for dinner and drinks.

¶6       That same day, Prante and his friend, John Scroggins, were next door at the
     home of Paul Main, drinking and partying. At trial, Scroggins testified that he saw
     Brown, whom he knew from school, and said hello to her outside the house. He
     also introduced her to Prante. The three spoke briefly, and Scroggins and Prante
     then returned to Main’s house. Thereafter, according to Scroggins, Prante began
     talking about Brown, telling Scroggins “how good” she looked and how he was
     particularly interested in her “chest.” Scroggins stated that Prante showed “more
     interest” in Brown than he had with other women, seemed to be excited about her,
     and kept bringing the conversation back to her. When Prante drove Scroggins home
     later that evening, he again talked about Brown. Prante was also “upset” and
     “irritated” that he could not join the gathering of friends at Brown’s house.

¶7       The next morning, on June 21, 1978, Fair went to work, leaving Brown home
     alone. Sometime between 10 and 11 a.m., Brown spoke with Fair’s mother on the
     phone. The conversation ended when Brown said that someone was at the door.

                                             -2-
¶8         At approximately 10:45 a.m., Edna Moses was driving with her six-year-old
       grandson, Eric Moses, on the street where Brown lived. Realizing that she was
       heading in the wrong direction, Edna pulled into the driveway of Brown’s house to
       turn around. As she did so, she saw a man and a woman standing near the garage,
       talking. The woman, who matched Brown’s description, turned and walked toward
       the house with the man following after her. Eric testified that he also saw the man
       and woman. He stated that the woman was wearing a short-sleeved shirt with
       flowers on it and that she “sort of got mad at” the man.

¶9        At approximately 11 a.m., Brown’s friend Debbie Davis stopped by Brown’s
       house to visit. She knocked on the front and back doors but left when there was no
       answer. She did not see anyone on the porch next door. Between noon and 2:30
       p.m., Davis and two other friends phoned Brown’s home but, again, got no answer.

¶ 10      Fair returned home from work at approximately 5 p.m. with his friend Tom
       Fiegenbaum. Fair went into the house, calling for Brown. He made his way to the
       basement, where he saw the room in disarray and blood “all over” the floor and
       couch. As he was turning to run back upstairs, he glanced into the basement laundry
       room and saw Brown’s body.

¶ 11       Brown was bent over at the waist, with her head and shoulders inside a metal
       barrel. The barrel, which had been used to store clothes, was filled with water.
       Brown’s hands were tied behind her back with a white extension cord, and two
       men’s socks were tied around her neck. She was wearing a heavy sweater that she
       normally wore only in the winter and was naked from the waist down. She also had
       large cuts on her forehead and chin. Fair immediately lifted Brown’s body out of
       the barrel and laid her on the floor. Fiegenbaum called the police, who arrived
       within a few minutes.

¶ 12       Wood River police chief Ralph Skinner testified that he arrived at Brown and
       Fair’s home at approximately 6 p.m. He stated that the area was secured and that
       no civilians were allowed in the home while the crime was being investigated.

¶ 13      Wood River police detective Charles Nonn arrived at the crime scene about 20
       minutes after Chief Skinner. He stated that he saw two men, whom he identified as
       Prante and Main, standing in Main’s front yard.

                                              -3-
¶ 14       Police investigating the crime scene found blood splattered on the basement
       floor and a bloodied couch cushion heavily saturated with water. A blood-stained
       tampon was found on a coffee table near the couch, and a stand of TV trays was
       overturned. A coffee pot from a coffee maker kept in the kitchen was found in the
       rafters of the laundry room. A fingerprint was recovered from the coffee pot, but it
       did not match Prante’s prints or anyone else whose prints were submitted for
       comparison.

¶ 15       Dr. Harry Parks performed an autopsy on Brown. At trial, he testified that she
       had suffered a fractured jaw, several bruises, and severe scraping around her throat
       that he believed was consistent with strangulation. She also had lacerations on her
       forehead, nose, and chin that were caused by a blunt object. Dr. Parks concluded
       that the cause of Brown’s death was strangulation and that the time of death was
       approximately 11:45 a.m., although that time could have varied by several hours.

¶ 16       Prante was interviewed by Wood River police chief Skinner on June 24, 1978.
       During this interview, Prante told Chief Skinner that he and Scroggins were at
       Main’s house the day before the murder. They saw Brown and Fair moving in with
       the help of several other people and then having a party. According to Prante,
       Scroggins said that he knew Brown and that they ought to go over to the party, but
       they never did.

¶ 17       Prante also told Chief Skinner that the next morning, around 8:30 a.m., he went
       to Main’s house to see if Main wanted to go to St. Louis to drop off some job
       applications. Main could not go, however, because he had a job painting a house,
       so Prante went by himself. Prante told Chief Skinner that, after dropping off the job
       applications, he “bummed around or stopped by somewhere.” Prante said that he
       did not see Main again until approximately 6 p.m. at the home of his friend Harold
       Pollard. While there, Main told Prante that Brown had been killed.

¶ 18       On July 5, 1978, Prante was interviewed by Wood River police detective Eldon
       McEuen. During this interview, Prante again confirmed that he had been at Main’s
       house the day before the murder and had watched the party next door. Prante told
       Detective McEuen that he was “very much aware of this young lady that lived
       there” and that “he felt she was beautiful.” Prante stated that he had wanted to join
       the party, but he had not been invited.

                                               -4-
¶ 19       Prante also told Detective McEuen that the next morning he went to Main’s
       house to see if Main wanted to drop off job applications. However, Main was busy
       painting a house, so Prante went alone. When Detective McEuen asked Prante if he
       had returned to Main’s house after that, Prante said “he wasn’t sure if he did or
       didn’t.”

¶ 20       Main’s aunt, Edna Vancil, lived across the street from Main. At trial, she
       testified that she saw Prante, whom she had known for eight or nine years, arrive at
       Main’s house between 9:30 and 10 a.m. on the day of the murder. She stated that
       Main had been painting a house but joined Prante on Main’s front porch. According
       to Ms. Vancil, the two sat on the porch, “smoking pot and drinking beer” and then
       “disappeared from eleven o’clock until almost twelve o’clock.” They then returned
       to the porch and stayed there until approximately 3 p.m. when Prante left. Ms.
       Vancil spoke to police on the night of the murder, but she was not asked any
       questions about Prante at that time.

¶ 21       Two years after the murder, in the summer of 1980, Wood River police
       investigators sent photographs of Brown’s body that had been taken at the crime
       scene and during the autopsy to Dr. Homer Campbell, a forensic dentist and expert
       in image enhancement. The photographs were black and white and were unscaled,
       meaning that there was no ruler or other measuring standard placed next to the body
       to establish the size of any wounds. After reviewing the photographs, Dr. Campbell
       informed the police that there were bite marks on Brown’s right collarbone. Prior
       to this, no police officer or other official had been aware of the possible existence
       of bite marks on Brown’s body.

¶ 22       Nearly two years later, in March 1982, police investigators decided to exhume
       Brown’s body and conduct a second autopsy. As part of an intentional media
       campaign, police notified reporters about the exhumation, told them about the
       purported bite marks on Brown’s collarbone, and indicated that they were nearing
       an arrest.

¶ 23       Brown’s body was exhumed on June 1, 1982, and a second autopsy was
       performed by Dr. Mary Case. Her findings largely confirmed those of the first
       autopsy, although she opined that drowning was the cause of death rather than
       strangulation. Dr. Case also examined the wounds on Brown’s collarbone, which

                                               -5-
       had been identified as bite marks, and testified that the injuries occurred at or near
       the time of death.

¶ 24       Following the exhumation of Brown’s body and the accompanying publicity,
       four friends of Prante’s—Vicki White, Mark White, Spencer Bond, and Roxanne
       Bond—came forward with information for the police. All four testified at trial.

¶ 25       Vicki White testified that within three days of the murder she and Mark White,
       her then-husband, were at the home of Spencer Bond and his wife Roxanne.
       According to Vicki, Prante entered the house and began talking about Brown.
       Prante stated that Brown “was murdered and that her body was down in her
       basement, and she was in a curled up position, and she had teeth marks on her
       body.” Vicki testified that, when Prante mentioned the teeth marks, he made a
       gesture by putting “his arm over his shoulder.” Vicki also stated that Prante was
       “nervous” and that he told the group that he was at Brown’s house on the day of
       the murder but that Brown was “all right” when he left. Prante also told them that
       “he had to get his story straight and he had to get out of town because the police
       were looking for him.”

¶ 26       Mark White also testified that, within a few days of the murder, he and Vicki
       were at the home of Spencer and Roxanne Bond when Prante arrived. Prante was
       “nervous” and acting “strange” and brought up the subject of Brown’s murder.
       Prante told the group that he knew Brown and had been over to her house on the
       day of the murder and was supposed to return there that evening. Although Prante
       did not say why he was at Brown’s house, Mark testified that he had a “feeling”
       that “it was probably to go over there to have sex with her.” Mark stated that while
       Prante was talking to Spencer, Prante “made a gesture of putting his hand up to his
       shoulder,” although he did not hear what Prante said. Mark also stated that Prante
       told the group he was going to be questioned by the police about Brown’s murder
       and that he was afraid that “he could have been the last one to see her alive.”

¶ 27       Spencer Bond similarly testified that Prante came to his house and discussed
       the murder a few days after it happened. According to Spencer, Prante was “a little
       agitated” and “more nervous” than usual and said that he and Main “had to get their
       stories together as to what they were doing that day” “so the police wouldn’t be
       able to crack his alibi.” Prante stated that he was at Main’s house the day of the
       murder. Main had been painting a house next door and then joined Prante in

                                               -6-
       “getting drunk and getting high.” Prante said that he talked to Brown at about 2 or
       3 p.m. and that he “was supposed to go back and see her because he might have a
       possible date with her.” Prante also said that “the girl was in a curled position stuck
       in a pail of water down in the basement,” “had teeth marks on her shoulder where
       she had been bitten,” and “had been tied up.”

¶ 28       Roxanne Bond also testified that Prante was at her house with Spencer, Mark,
       and Vicki. However, Roxanne stated that she did not hear any of the group’s
       conversation because she was busy taking care of her daughter. Roxanne did recall
       Prante saying on one occasion that “he had to get his story straight,” but she could
       not remember when he said it.

¶ 29       After speaking with police investigators, Spencer had two conversations with
       Prante while secretly wearing a recording device. In these conversations, Prante
       acknowledged that, on the day of the murder, he was on Main’s front porch from
       10 or 11 a.m. until evening and that he saw Brown “putterin’ around outside.” He
       also said that he may have spoken with Brown on the “walkway” but did not go
       into her house. Prante further stated that, after the police arrived, Brown’s house
       was sealed off and no one could have gotten inside. Prante also told Spencer that
       he was “not guilty of anything,” did not “remember the bite marks,” and “didn’t
       know nothin’ about it.”

¶ 30       Harold Pollard, who had known Prante for approximately 11 years, also
       testified at trial. Pollard stated that, on the day of the murder, Prante came to his
       house at approximately 6:30 or 7 p.m. Prante seemed “agitated” and “anxious” and
       asked Pollard if he “had any tranquilizers that he could use.” Prante told Pollard
       that he had just come from Main’s house where he had been “smoking pot and
       drinking beer” and that the girl next door had been murdered or killed. Prante said
       that Brown’s “body was found curled up on the floor with its hands tied behind its
       back.” When Pollard asked Prante how he knew this, Prante said “he got a glimpse
       of the girl by looking over the policeman’s shoulder at the crime scene” inside the
       house. According to Pollard, Main came to his house sometime after Prante arrived,
       and the two exchanged comments about the murder. Pollard also testified that, a
       day or two earlier, Prante had told Pollard that Brown was “a really nice looking
       girl” and “he wouldn’t mind, you know, having relations with her.”

                                                -7-
¶ 31       Susan Lutz, who had previously had a sexual relationship with Prante, also
       testified. Ms. Lutz stated that on a couple of occasions Prante bit her on the neck
       during sex. She also stated that Prante once whispered in her ear after having sex
       that “he had killed a woman.” When Ms. Lutz asked why he had killed the woman,
       Prante said “he was mad” but offered no other explanation, stating that he could not
       talk about it because he would “lose [his] freedom.”

¶ 32       The State offered the testimony of two forensic dentists, Dr. Campbell and Dr.
       Lowell Levine. Dr. Campbell testified that bite mark analysis had improved in
       recent years and had gained wide acceptance among pathologists. He explained that
       “[e]verybody’s dentition is individual” and compared dental impressions to
       fingerprints. He further stated that human skin was a “very excellent” medium for
       bite marks and an “excellent reproducer of tooth characteristics.”

¶ 33       Dr. Campbell testified that the autopsy photographs of Brown “definitely”
       showed at least three overlapping human bite marks on her right collarbone. Dr.
       Campbell compared the bite marks in the photographs to the dental impressions of
       Prante, Main, and two other individuals. According to Dr. Campbell, Prante’s teeth
       were “consistent with” the bite marks, meaning that his “teeth could have made the
       bite marks, period.” The teeth of the other individuals, however, could not. Dr.
       Campbell acknowledged that the autopsy photographs were black and white rather
       than color and were unscaled. Nevertheless, Dr. Campbell stated there was nothing
       about the quality of the photographs or the process by which they were taken that
       altered his opinion that the bite marks were consistent with Prante’s teeth.

¶ 34       Like Dr. Campbell, Dr. Levine similarly compared bite mark analysis to
       fingerprint analysis, stating that bite mark analysis “really is no different than a
       fingerprint person looking at the characteristics left by a bloody handprint on a
       wall” and that different persons cannot leave identical bite marks. He further stated
       that human “skin can capture the unique and individual characteristics of the teeth
       with *** excellent fidelity.” Dr. Levine testified that there were bite marks shown
       in the autopsy photographs. He stated that Prante’s teeth “could have caused that
       injury pattern” and further that, if only the teeth of Main and Prante were
       considered, he “would have to say [the bite marks] had to be left by Mr. Prante.”

                                               -8-
¶ 35       The State also called Prante’s own dentist, Dr. Ronald Mullen, to testify. He
       stated that he saw 6000 to 7000 patients a year and that the spacing in Prante’s teeth
       was very unique, so much so that less than 1% of his patients had teeth like that.

¶ 36       Dr. Edward Pavlik, a forensic odontologist, testified on Prante’s behalf. Dr.
       Pavlik stated that there were several problems with the autopsy photographs that
       purportedly showed bite marks: the photographs were not taken at the correct angle,
       there was no scale present for purposes of comparison, and the pathologist appeared
       to be pulling on the skin in one photograph, thereby causing distortion. Dr. Pavlik
       stated that the photographs were “one step above useless” and there was “very little
       evidence *** to even substantiate that we have a bite mark.” When asked to assume
       that the injury in the photographs was a bite mark, Dr. Pavlik stated that Prante’s
       teeth were consistent with the mark but that as much as 10% of the adult population
       had spacing of their teeth similar to Prante’s.

¶ 37       A second forensic odontologist, Dr. Norman Sperber, also testified that the
       autopsy photographs were not “suitable” for making bite mark comparisons and
       that, given their poor quality, he had “no way of knowing” what he was looking at.
       Dr. Sperber stated that the injuries in the photographs “resembled other things” as
       well as bite marks and he was “not sure that there are any bite marks shown.” Dr.
       Sperber also stated that attempting to identify a bite mark from such poor-quality
       photographs would be akin to “witchcraft or opinion.” When asked to assume that
       the injuries were bite marks, Sperber stated that, at most, it was “possible” Prante’s
       teeth made them.

¶ 38       Prante testified on his own behalf. Prante stated he had “virtually no memory”
       of the day of the murder but that his memory had “improved over the last year”
       when he started reading the discovery in the case and “things started clicking back
       into place.” He acknowledged that he and Scroggins were at Main’s house the
       evening before the murder and that Scroggins had gone over and talked to Brown.
       Prante denied, however, that Scroggins had introduced Brown to him.

¶ 39       Prante stated that, on the day of the murder, he went to Main’s house around 8
       or 8:30 a.m. and then left to drop off some job applications. He returned to Main’s
       house sometime between 10 a.m. and 1 p.m. and then “sat around” on the front
       porch and “probably got high again.” When asked how long he stayed on the porch,
       Prante stated, “I keep having this feeling that I was there all day; that I stayed the

                                               -9-
       entire day; that it just keeps coming to mind.” He also stated that he may have left
       the porch at one point to see the house that Main was painting and may have gone
       to the store.

¶ 40       Prante acknowledged seeing Brown on the day of the murder. According to
       Prante, she was “out in the front yard puttering around” sometime in the morning
       or early afternoon and was wearing “white shorts and like a white flowered top.”

¶ 41       Prante testified that he remembered being on the front porch when police
       arrived following the murder and then going inside Main’s house with Main. He
       stated that he left Main’s house in the early evening and then went to Pollard’s
       house. He further stated that he first learned of the murder when Main told him
       about it at Pollard’s house.

¶ 42       Prante acknowledged that, when he was first interviewed by Chief Skinner, he
       told him that on the day of the murder he did not return to Main’s house after
       dropping off the job applications. Prante explained that he must have made this
       statement due to a “memory problem” or “confusion.” Prante denied making the
       statements attributed to him by Pollard, Lutz, Spencer Bond, and Mark and Vicki
       White and denied ever biting Lutz. He also denied killing Brown.

¶ 43      Following arguments, the jury found Prante guilty of murdering Brown. He was
       subsequently sentenced to 75 years’ imprisonment.

¶ 44       On direct appeal, the appellate court rejected Prante’s claim that the State’s
       expert testimony concerning the bite marks should not have been admitted. People
       v. Prante, 147 Ill. App. 3d 1039, 1062 (1986). The court held that Prante had waived
       the issue and, in the alternative, that the trial court did not abuse its discretion in
       “allowing expert testimony concerning bite marks to aid comparison between the
       wounds on the victim’s right shoulder and the dentition of the defendant.” Id.

¶ 45       In 1993, Prante filed a postconviction petition in which he raised a claim of
       ineffective assistance of counsel and a due process claim based on “material
       misrepresentation of evidence relating to evidence of blood found at the crime
       scene.” The circuit court dismissed the petition as untimely, and the appellate court
       affirmed the dismissal. People v. Prante, 275 Ill. App. 3d 1153 (1995) (table)
       (unpublished order under Illinois Supreme Court Rule 23).

                                               - 10 -
¶ 46       In 2002, Prante filed a petition for relief from judgment in which he contended
       that his sentence violated Apprendi v. New Jersey, 530 U.S. 466 (2000). The circuit
       court dismissed the petition, and the appellate court affirmed the dismissal. People
       v. Prante, 369 Ill. App. 3d 1066 (2006) (table) (unpublished order under Illinois
       Supreme Court Rule 23).

¶ 47       In 2017, Prante filed a motion for DNA and fingerprint testing pursuant to
       section 116-3 of the Code of Criminal Procedure of 1963 (725 ILCS 5/116-3 (West
       2016)). He sought testing of several items of physical evidence as well as analysis
       of the fingerprint found on the coffeepot discovered in the laundry room rafters.
       The circuit court entered agreed orders for the testing. No interpretable DNA
       profiles were obtained, and no match was found for the fingerprint.

¶ 48       In 2018—35 years after he was convicted—Prante filed the motion seeking
       leave to file the successive postconviction petition that is at issue in this appeal. In
       his petition, Prante raised five claims: (1) a claim of actual innocence pursuant to
       People v. Washington, 171 Ill. 2d 475 (1996); (2) a separate due process claim
       alleging that his trial proceedings were rendered fundamentally unfair by the
       admission of bite mark analysis evidence; (3) ineffective assistance of trial counsel;
       (4) ineffective assistance of appellate counsel; and (5) cumulative error.

¶ 49       Prante attached to his petition two affidavits from Dr. Iain Pretty, an expert in
       forensic odontology. In these affidavits, Dr. Pretty averred that at the time of
       Prante’s trial “the use of bitemark evidence was a well-accepted forensic technique,
       generally understood by its practitioners and by the scientific community to be valid
       and reliable.” However, since the time of Prante’s trial, that understanding has
       “shifted significantly” as a result of new research and scientific review. In light of
       this new research, Dr. Pretty stated there is no “evidence to support the fact that
       forensic dentists can even agree on what a bitemark is—never mind the more
       advanced proposal that this pattern may actually be linked to someone.” (Emphasis
       in original.) Further, according to Dr. Pretty, “even board-certified forensic dentists
       cannot reliably answer the threshold inquiry in bitemark analysis: whether the
       injury at issue is or is not a bitemark.” Dr. Pretty stated that the conclusions “drawn
       by the forensic dentists in [this] case, even at the level of identifying these injuries
       as human bitemarks, would not be supported [by the scientific community] today.”

                                                - 11 -
¶ 50       Prante also appended three reports on bite mark analysis to his petition, all of
       which were referenced by Dr. Pretty: a 2009 report of the National Academy of
       Sciences (Nat’l Acad. of Sci., Strengthening Forensic Science in the United States:
       A Path Forward (2009), https://www.ojp.gov/pdffiles1/nij/grants/228091.pdf
       [https://perma.cc/J2NU-CYYM]), a 2016 report from the President’s Council of
       Advisors on Science and Technology (President’s Council of Advisors on Sci. and
       Tech., Forensic Science in Criminal Courts: Ensuring Scientific Validity of
       Feature-Comparison Methods (2016), https://obamawhitehouse.archives.gov/
       sites/default/files/microsites/ostp/PCAST/pcast_forensic_science_report_final.pdf
       [https://perma.cc/5KTD-C4DF]), and a 2016 report from the Texas Forensic
       Science Commission (Tex. Forensic Sci. Comm’n, Forensic Bitemark Comparison
       Complaint Filed by National Innocence Project on Behalf of Steven Mark Chaney—
       Final Report (2016), https://www.txcourts.gov/media/1454500/finalbitemark
       report.pdf [https://perma.cc/EGX5-V6JW]).

¶ 51       These three reports were uniform in concluding that bite mark analysis is not
       scientifically valid. According to these reports, it has not been scientifically
       established that human bite marks are unique or that human skin can record those
       marks with accuracy and permanency. Further, there is no scientific basis for
       identifying one individual to the exclusion of all others based on bite mark analysis
       and no basis for stating that a particular injury can be associated with an
       individual’s dental impressions.

¶ 52       Prante also attached to his petition an affidavit from Dr. Nancy Franklin, a
       professor of psychology who studies cognition and false memories. Dr. Franklin
       discussed limitations and biases that may affect human memory and averred that
       these limitations likely affected the ability of several witnesses to accurately recall
       the details of their conversations with Prante.

¶ 53       The circuit court denied Prante leave to file all claims. On appeal, the appellate
       court reversed the judgment of the circuit court with respect to Prante’s due process
       claim. 2021 IL App (5th) 200074. Addressing that claim, the appellate court
       focused on whether bite mark analysis is “scientific evidence” that must satisfy the
       general acceptance test of Frye v. United States, 293 F. 1013 (D.C. Cir. 1923), to
       be admitted at trial. 2021 IL App (5th) 200074, ¶¶ 63-87. The appellate court
       concluded that bite mark analysis is scientific evidence within the meaning of Frye

                                               - 12 -
       but that no Illinois court had ever subjected bite mark analysis to the Frye test. Id.
       ¶ 77. The appellate court also concluded that Prante had made a prima facie
       showing of cause and prejudice and, therefore, that “the circuit court erred in
       denying the petitioner leave to file his successive postconviction petition on this
       basis.” Id. ¶ 87. The appellate court then affirmed the judgment of the circuit court
       denying Prante leave to file his claim of actual innocence (id. ¶¶ 89-97) but did not
       address Prante’s remaining claims.

¶ 54       We allowed the State’s petition for leave to appeal. Ill. S. Ct. R. 315 (eff. Oct.
       1, 2020). Prante has requested cross-relief from the appellate court’s judgment
       denying him leave to file his claim of actual innocence. Ill. S. Ct. R. 318(a) (eff.
       Oct. 1, 2020).

¶ 55                                        ANALYSIS

¶ 56       At the outset, we take judicial notice of the fact that Prante, who was sentenced
       in 1983 under the day-for-day, good-time credit scheme (Ill. Rev. Stat. 1981, ch.
       38, par. 1003-6-3(a)(2)), has now fully served his sentence, including any period of
       parole or mandatory supervised release. However, this fact does not affect our
       disposition of this appeal.

¶ 57       Section 122-1(a) of the Post-Conviction Hearing Act (Act) (725 ILCS 5/122-
       1(a) (West 2016)) requires that the petitioner be imprisoned at the time the
       postconviction proceedings are “instituted.” Here, there is no dispute that Prante
       was imprisoned when he filed his motion for leave to file his successive
       postconviction petition in 2018. The Act’s imprisonment requirement was therefore
       satisfied. See People v. Coe, 2018 IL App (4th) 170359, ¶ 43 (“current
       imprisonment is a condition for ‘institut[ing]’ a postconviction proceeding, not for
       continuing to litigate it” (emphasis in original)). In addition, Prante’s interest “ ‘in
       purging [himself] of the stigma and disabilities which attend a criminal
       conviction’ ” prevents his case from being moot. Id. ¶ 50 (quoting People v. Davis,
       39 Ill. 2d 325, 329 (1968)). Accordingly, although Prante is no longer serving any
       sentence, we are not precluded from addressing the matters raised in this appeal.

¶ 58      At issue here is the circuit court’s denial of Prante’s motion for leave to file a
       successive postconviction petition under the Act (725 ILCS 5/122-1 et seq. (West

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       2016)). The Act provides the statutory means for a criminal defendant to assert that
       “in the proceedings which resulted in his or her conviction there was a substantial
       denial of his or her rights under the Constitution of the United States or of the State
       of Illinois or both.” Id. § 122-1(a)(1). “The Act is not a substitute for an appeal, but
       rather, is a collateral attack on a final judgment.” People v. Edwards, 2012 IL
       111711, ¶ 21.

¶ 59        Both the Act and our caselaw make clear that the filing of only one
       postconviction petition is contemplated. 725 ILCS 5/122-3 (West 2016) (“Any
       claim of substantial denial of constitutional rights not raised in the original or an
       amended petition is waived.”); People v. Robinson, 2020 IL 123849, ¶ 42.
       However, there are two exceptions to the bar against successive proceedings. The
       first is the “cause and prejudice” exception, which has been codified in the Act. See
       725 ILCS 5/122-1(f) (West 2016). The second, the “fundamental miscarriage of
       justice” exception, requires a petitioner to make a persuasive showing of “actual
       innocence.” People v. Taliani, 2021 IL 125891, ¶ 55. Under either exception, a
       petitioner seeking to file a successive postconviction petition must first obtain leave
       of court. Id. ¶ 58. A circuit court’s denial of a petitioner’s motion for leave to file a
       successive petition is subject to de novo review. Id. ¶ 52.

¶ 60                                     Due Process Claim

¶ 61       In his postconviction petition, Prante raises a due process claim in which he
       alleges that the admission of bite mark analysis evidence rendered his trial
       fundamentally unfair. Prante contends (and the State agrees) that, for purposes of
       deciding whether he should be granted leave to file this claim, we must take as true
       the conclusions reached in the materials attached to Prante’s postconviction
       petition. This means that we must assume that bite mark analysis, i.e., expert
       opinion testimony comparing an injury on human skin to the dental impressions of
       another person, has been thoroughly discredited. Prante asserts that the “admission
       of scientific evidence now found to be invalidated and unreliable” means that he
       was convicted “in violation of due process” and is therefore entitled to a new trial.
       Prante further asserts that he has satisfied the cause and prejudice test and,
       therefore, should be permitted to go forward with this claim.

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¶ 62       The circuit court denied Prante leave to file his due process claim, but the
       appellate court reversed the circuit court’s ruling. In doing so, however, the
       appellate court did not adopt Prante’s characterization of the claim. Rather than
       applying a due process analysis, the appellate court engaged in an extensive
       discussion of the Frye general acceptance test that is used when considering the
       evidentiary admission of new scientific principles or methodologies. 2021 IL App
       (5th) 200074, ¶¶ 63-87. The appellate court determined that bite mark analysis is
       subject to the Frye test and noted that no Illinois court has ever held a Frye hearing
       for bite mark analysis. In addition, the appellate court’s analysis and ruling
       appeared to require the circuit court to conduct a Frye hearing on remand to that
       court. Id. ¶ 95 (noting that “it remains to be determined how the Frye analysis will
       determine the scope, if at all, of the admission of comparison testimony”). The
       appellate court concluded its discussion by stating:

              “Since [Prante’s] trial, the law regarding the admissibility of scientific
          evidence has developed, to the extent that bite mark evidence would now be
          considered ‘scientific’ evidence that must withstand a Frye analysis.
          Furthermore, the petition effectively alleges, and supports with documentation,
          a recent change within the scientific community regarding the validity and
          reliability of bite mark evidence, suggesting that the evidence presented by the
          State at [Prante’s] trial is no longer generally accepted within the scientific
          community. We find that the petition made a prima facie showing of cause and
          prejudice and that the circuit court erred in denying the petitioner leave to file
          his successive postconviction petition on this basis.” Id. ¶ 87.

¶ 63       From this, it appears the appellate court determined that Prante’s due process
       claim required an examination of the Frye test and that the trial court’s failure to
       hold a Frye hearing before admitting the bite mark evidence was a constitutional
       violation. This was error by the appellate court.

¶ 64       Relief under the Act is limited to constitutional violations that occurred at trial.
       People v. Coleman, 183 Ill. 2d 366, 380 (1998). The Frye test is a common-law
       evidentiary rule, adopted by this court and codified in the Illinois Rules of
       Evidence. See Ill. R. Evid. 702 (eff. Jan. 1, 2011). The Frye test is not a
       constitutional rule, and the failure to comply with Frye is not, in itself, a
       constitutional violation. Milone v. Camp, 22 F.3d 693, 702 (7th Cir. 1994).

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       Accordingly, Prante’s due process claim cannot go forward on the grounds offered
       by the appellate court. 1

¶ 65       Prante contends that, even if the appellate court erred by focusing its analysis
       on Frye, he has nevertheless set forth a cognizable constitutional violation by
       alleging that the admission of bite mark analysis evidence violated his right to due
       process. He maintains, therefore, that he should be permitted to proceed with this
       claim.

¶ 66       Both the federal and state constitutions protect against “conviction based on
       evidence of questionable reliability.” Perry v. New Hampshire, 565 U.S. 228, 237
       (2012). Ordinarily, though, this protection is provided not by the due process clause
       but by other constitutional guarantees, such as the right to counsel and the right to
       confrontation, as well as various other nonconstitutional evidentiary rules. Id.
       However, when evidence “ ‘is so extremely unfair that its admission violates
       fundamental conceptions of justice,’ ” the due process clause prohibits its use. Id.
       (quoting Dowling v. United States, 493 U.S. 342, 352 (1990)); see also, e.g., United
       States v. Sanders, 708 F.3d 976, 983 (7th Cir. 2013) (“when evidence is so
       extremely unfair that its admission violates fundamental conceptions of justice, due
       process, like the sleeping giant, awakens” (internal quotation marks omitted));
       People v. Cornille, 95 Ill. 2d 497, 508-09 (1983).

¶ 67       In this case, Prante acknowledges that he was permitted to fully cross-examine
       the State’s forensic dental experts, Drs. Campbell and Levine, regarding their
       conclusions that bite marks found on Brown’s body were consistent with Prante’s
       teeth, and he was able to present his own expert witnesses to challenge those
       conclusions. Prante asserts, however, that his trial was nevertheless unfair because
       we now know that bite mark analysis is not a proper subject for expert testimony
       and that the testimony of Drs. Campbell and Levine was, in fact, false. As Prante
       explains, in light of recent scientific developments, we now know that, when Drs.
       Campbell and Levine each stated that bite mark analysis is the equivalent of
       fingerprint analysis, those statements were not true. Similarly, their statements, that

           1
             Confusingly, the appellate court at times also referred to Prante’s due process claim as “the
       petitioner’s cause and prejudice claim.” 2021 IL App (5th) 200074, ¶ 97. The cause and prejudice
       test is the analytical tool used to determine whether a procedurally defaulted constitutional claim
       may be considered on its merits. The cause and prejudice test is not the underlying claim itself.

                                                     - 16 -
       human skin is an excellent medium for recording bite marks and that every
       individual’s dentition is unique, also were not true. According to Prante,
       “[e]veryone in the courtroom—from the State, the defense, the jury and the judge—
       were operating under a false premise: bite mark evidence was valid and reliable
       ‘scientific’ evidence. It was not.” Prante further asserts that the false bite mark
       testimony was emphasized by the State throughout the trial and, in this way,
       rendered the proceedings fundamentally unfair. Accordingly, Prante contends that
       he has pled a cognizable due process claim. We disagree.

¶ 68       Prante’s due process claim is foreclosed by this court’s decision in People v.
       Brown, 169 Ill. 2d 94 (1995). In Brown, the defendant filed a postconviction
       petition alleging that he was denied his constitutional right to a fair trial because his
       convictions were based on the false testimony of one of the State’s witnesses. Id. at
       95-96. The circuit court summarily dismissed the petition, and this court affirmed
       the dismissal. Id. at 96. In so doing, this court noted that both Illinois courts and the
       federal circuit courts were divided over whether a criminal defendant must show
       that the government’s use of false testimony was knowing in order to establish a
       constitutional violation. Id. at 103-06. After acknowledging this split of authority,
       this court stated:

           “[W]e find that the better rule is the one expressed in those cases requiring an
           allegation of knowing use of false testimony in order to establish a
           constitutional violation. In the absence of an allegation of the knowing use of
           false testimony, or at least some lack of diligence on the part of the State, there
           has been no involvement by the State in the false testimony to establish a
           violation of due process. (See Cornille, 95 Ill. 2d at 513.) Without such
           involvement, the action of a witness falsely testifying is an action of a private
           individual for which there is no remedy under the due process clause.” Id. at
           106.

¶ 69       Under Brown, a defendant must allege that the State’s use of false testimony
       was knowing in order to establish a constitutional violation. In this case, Prante has
       not done so. There are no allegations in Prante’s motion or postconviction petition
       that the State knew or should have known that the testimony of Drs. Campbell and
       Levine was false. To the contrary, Prante acknowledges that at the time of trial it

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       was assumed by all parties that, although experts might disagree in individual cases,
       the principles underlying bite mark analysis were valid and true.

¶ 70       In support of his due process claim, Prante cites federal decisions that have
       recognized a due process claim where the defendant alleges the improper admission
       of subsequently discredited forensic evidence. See, e.g., Lee v. Houtzdale SCI, 798
       F.3d 159, 162 (3d Cir. 2015) (fire science and gas chromatography); Ege v. Yukins,
       485 F.3d 364, 375-78 (6th Cir. 2007) (bite marks). These decisions are inapposite.
       They do not apply Illinois law, nor do they recognize the rule adopted by this court
       in Brown.

¶ 71       In the absence of any allegation that the State knowingly used the false bite mark
       testimony or that the State failed to exercise diligence to discover that the testimony
       was false, Prante has not pled a cognizable due process claim under Illinois law.
       Accordingly, the circuit court properly denied Prante leave to file his due process
       claim. We therefore reverse the judgment of the appellate court allowing Prante to
       go forward on that claim. Because he has not pled a cognizable due process claim
       under Illinois law, we need not consider whether Prante has satisfied the cause and
       prejudice test.

¶ 72                                 Actual Innocence Claim

¶ 73       In his postconviction petition, Prante raises as his “primary ground for relief” a
       claim of actual innocence pursuant to Washington, 171 Ill. 2d 475. In Washington,
       this court recognized a “freestanding” claim of actual innocence as a matter of state
       law under the due process clause of the Illinois Constitution of 1970 (Ill. Const.
       1970, art. I, § 2). Washington, 171 Ill. 2d at 485-90. We explained that such a claim
       is one in which newly discovered evidence is not being used to “supplement an
       assertion of a constitutional violation” with respect to the petitioner’s trial. Id. at
       479-80. Instead, a freestanding claim of actual innocence is one in which it is
       alleged that newly discovered evidence makes a persuasive showing that the
       petitioner did not commit the offense with which he was charged and was,
       therefore, wrongfully convicted. Id. at 489.

¶ 74       To obtain relief when raising a claim of actual innocence, the newly discovered
       evidence offered by the petitioner must be material, noncumulative, and of such a

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       conclusive character that it would “ ‘probably change the result on retrial.’ ” Id.
       The new evidence must place the trial evidence in a different light and undermine
       the court’s confidence in the factual correctness of the guilty verdict. People v.
       Coleman, 2013 IL 113307, ¶ 97. Where, as here, a petitioner raises an actual
       innocence claim in a motion for leave to file a successive postconviction petition,
       the petitioner should be denied leave to file only where, as a matter of law, no
       colorable claim of actual innocence has been presented. Edwards, 2012 IL 111711,
       ¶¶ 31-33. This simply means that the petitioner must produce newly discovered
       evidence that, when considered along with all the evidence presented at trial, would
       probably lead to a different result on retrial. Taliani, 2021 IL 125891, ¶ 59.

¶ 75       In this case, the parties’ dispute centers primarily on the conclusive character
       of Prante’s evidence regarding the shift in scientific understanding that has taken
       place with respect to bite mark analysis. Because bite mark analysis has been
       discredited, Prante argues that, in any retrial, the State would not be permitted to
       introduce expert opinion testimony identifying the wound on Brown’s right
       collarbone as a bite mark and would not be permitted to introduce any testimony
       comparing that wound to dental impressions of Prante’s teeth. Given this fact,
       Prante contends that his newly proffered evidence is of such conclusive character
       as to warrant relief.

¶ 76       In support of this contention, Prante focuses largely on the testimony of Vicki
       White and Spencer Bond and their statements that Prante told them he had seen bite
       marks on Brown’s shoulder or collarbone at a time when the public had not yet
       been told of any such injury. Prante contends that, “[i]f the State cannot tell the jury
       there are bite marks at all, there is no point of the testimony” and, without that
       evidence, “a huge portion of the State’s case unravels.” Thus, according to Prante,
       he has presented conclusive new evidence that merits postconviction relief. We
       disagree.

¶ 77       Even assuming that, in a retrial, the State would not be permitted to introduce
       expert testimony identifying a bite mark on Brown’s collarbone, there would be no
       bar to admitting Prante’s statements that he, himself, saw a bite mark. Nor would
       there be any prohibition to the State offering testimony that there was a wound (of
       unknown cause) on Brown’s collarbone. Thus, even without the expert testimony
       identifying a bite mark, a jury would still hear evidence that Prante was aware of

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       an injury on Brown’s body that could only have been known by someone who
       participated in the murder.

¶ 78       Further, Prante’s statements describing the crime scene were not limited to
       saying that he saw a bite mark. He told Spencer Bond that Brown was found “in a
       curled position stuck in a pail of water down in the basement” and similarly told
       Vicki White and Harold Pollard that she was found in a “curled position” in the
       basement. Prante also told Spencer and Pollard that Brown had “been tied up” or
       had her “hands tied behind [her] back.” None of this evidence would be affected by
       the exclusion of the expert testimony regarding bite mark analysis.

¶ 79       Prante notes that none of the witnesses who testified regarding Prante’s
       statements shared those statements with police near the time of the murder. Prante
       points to the affidavit from Dr. Franklin attached to his petition that discusses false
       memories and contends this is new evidence that supports the conclusion that the
       witnesses’ testimony was tainted and that they only testified as they did because of
       reports discussing the crime they heard in the media after Brown’s body was
       exhumed and the second autopsy was conducted. Prante contends that this is an
       additional basis for allowing him to file his actual innocence claim. Here, too, we
       disagree.

¶ 80       Dr. Franklin’s affidavit is cumulative to evidence introduced at trial. The
       witnesses were questioned as to why they did not come forward earlier with their
       information regarding Prante. They explained that the police either did not ask them
       about Prante or they were unaware that his statements about seeing Brown’s body
       were important. Further, impeachment evidence such as that offered in Dr.
       Franklin’s affidavit typically is insufficient to justify postconviction relief. People
       v. Ortiz, 235 Ill. 2d 319, 335 (2009).

¶ 81       Additional evidence presented by the State at trial is also unaffected by the shift
       in scientific understanding of bite mark analysis. Scroggins testified that Prante met
       and spoke with Brown the night before the murder, expressed a sexual interest in
       her, and was irritated that he could not join her party. Detective McEuen and Pollard
       also testified that Prante said Brown was “beautiful” and “nice-looking” and that
       he was sexually attracted to her.

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¶ 82       In addition, Prante admitted at trial that he was at Main’s house from
       approximately 10 a.m. until shortly after the police arrived in the evening. Ms.
       Vancil, Main’s aunt and neighbor, corroborated that account, stating that Prante
       was on Main’s front porch from about 10 a.m. to 11 a.m., “disappeared” for about
       an hour, and then returned to the porch around noon. Prante also admitted that he
       saw Brown in her front yard in the morning or early afternoon on the day of the
       murder and stated she was wearing a “white flowered top.” In one of the recorded
       conversations with Spencer Bond, Prante said that he may have spoken with Brown
       in the driveway that day. These statements are consistent with testimony by Edna
       and Eric Moses that they saw a man and a woman matching Brown’s description
       in her driveway and that the woman was wearing a floral top.

¶ 83       Additional evidence offered by the State showed that, later that evening, Prante
       told Pollard that Brown had been killed and stated that her “body was found curled
       up on the floor with its hands tied behind its back.” When asked by Pollard how he
       knew this, Prante claimed to have looked over a policeman’s shoulder at the crime
       scene. Yet Brown’s body was found in the basement, and the house had been
       secured by the police. Prante thus could not have seen Brown’s body in the way he
       described to Pollard.

¶ 84      Within a few days, Prante told Spencer Bond that Brown was found “in a curled
       position stuck in a pail of water down in the basement” and had “been tied up.”
       These were also facts that, at the time the statements were made, could only have
       been known by someone who participated in the murder.

¶ 85       In addition, when Prante was first interviewed by the police he could not
       account for his whereabouts around the time of the murder. Only later did he state
       that he was on Main’s porch at that time. Further, all the witnesses who spoke with
       Prante following the murder described him as nervous and agitated and stated he
       told them that he and Main had to get their stories straight.

¶ 86       Even absent the bite mark testimony, the State presented considerable evidence
       that Prante had the motive and opportunity to commit the crime and, most
       importantly, that he was aware of facts about the crime scene at a time when they
       could only have been known by someone who participated in the murder. As this
       court has noted, “[b]ecause a successive postconviction claim of actual innocence
       undermines the finality of a conviction obtained after a fair trial, a postconviction

                                              - 21 -
       petitioner seeking to file a claim of actual innocence is held to a high standard.”
       Taliani, 2021 IL 125891, ¶ 68. Having carefully reviewed the record, we conclude
       that Prante has not met the high standard for setting forth a colorable claim of actual
       innocence. The circuit court properly denied Prante leave to file his claim of actual
       innocence. Accordingly, we affirm that part of the appellate court’s judgment that
       affirmed the circuit court’s ruling with respect to that claim.

¶ 87                                    Remaining Claims

¶ 88        In his postconviction petition Prante also raised three additional claims,
       including claims of ineffective assistance of trial and appellate counsel. Because
       the appellate court allowed Prante to go forward on his separate due process claim,
       it did not reach these three additional claims. 2021 IL App (5th) 200074, ¶ 97. We
       therefore remand this cause to the appellate court to address the unresolved claims.
       See, e.g., People v. Lowery, 178 Ill. 2d 462, 473 (1997) (“where trial errors were
       raised but not ruled upon in the appellate court, it is appropriate for this court to
       remand the cause to the appellate court for resolution of those remaining issues”).

¶ 89                                      CONCLUSION

¶ 90       For the foregoing reasons, the judgment of the appellate court granting Prante
       leave to file his due process claim is reversed. The judgment of the appellate court
       denying Prante leave to file his claim of actual innocence is affirmed. The cause is
       remanded to the appellate court to resolve Prante’s remaining claims.

¶ 91      Appellate court judgment affirmed in part and reversed in part.

¶ 92      Cause remanded.

¶ 93      JUSTICES ROCHFORD and O’BRIEN took no part in the consideration or
       decision of this case.

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