In this Sept. 3, 2014 file photo, Daniel Holtzclaw, foreground, a former Oklahoma City police officer accused of sexual offenses against 13 women he encountered while on patrol, is led into a courtroom for a hearing in Oklahoma City. Holtzclaw was convicted in December 2015 on 18 charges, including first-degree rape, forcible oral sodomy and sexual battery, and sentenced to 263 years in prison. (Photo: AP/Sue Ogrocki, File)

A former Oklahoma City police officer who was convicted in 2015 of using his uniform to sexually abuse women he believed were vulnerable has continued to fight his 263-year sentence.

Daniel Holtzclaw contends his defense attorney was ineffective in arguing against the DNA evidence testimony used in convincing a jury that the ex-cop forced as many as 13 women to perform oral sex on him over two years of separate incidents.

A group of a half-dozen DNA experts now contend on his behalf that the evidence in one of the key samples is troubling—and may be grounds for overturning the verdict, they argue in a new public letter.

“During Mr. Holtzclaw’s trial, the DNA analyst drew conclusions that were inconsistent with her reported results and which may have been outside the realm of her expertise,” the experts write. “In addition, important information regarding the DNA results from the fly area of Mr. Holtzclaw’s pants was not fully disclosed during the DNA analyst’s trial testimony.”

The DNA experts are: Peter Gill, a British expert known for his analysis of the Amanda Knox case; Jane Goodman-Delahunty, an expert at Charles Sturt University in Australia; Suzanna Ryan, a California-based DNA scientist; Moses Schanfield, a former New York lab director now at George Washington University; George Schiro, a Mississippi-based lab director; and Brent Turvey, of the Alaska-based Forensic Criminology Institute. 

Holtzclaw was convicted in December 2015 on 18 counts, including four first-degree rape counts as well as forcible oral sodomy, sexual battery, procuring lewd exhibition and second-degree rape. Holtzclaw was acquitted on 18 other counts. The accusers were all black women, and many had criminal histories including drug abuse and prostitution arrests, which were brought up by the defense at trial.

But since the conviction, the case has drawn scrutiny from various onlookers, including some forensic scientists and journalists like the conservative commentator Michelle Malkin.

The half-dozen DNA experts originally filed an amicus brief earlier this year. It was rejected by the Oklahoma Court of Criminal Appeals in June. A subsequent closed doors meeting held by prosecutors excluded the Holtzclaw defense attorneys, and the talks focused on the DNA testimony provided by a now-retired expert.

But now the half dozen experts are taking their forensic arguments direct to the public, in a letter to journalists and other criminal justice observers. They contend that the closed doors meeting about the DNA expert have called into question the state’s motives.

“Whether or not the secret hearing centered around these issues is currently unknown,” they write.

The DNA panel contends:

  • A 17-year-old’s genetic profile that was found on the fly of Holtzclaw’s pants was not from vaginal fluid sources, as had been implied during testimony.
  • The prosecution did not test to see whether that DNA was from a vaginal source, using an alternate light source.
  • Cross-contamination through secondary transfer could have transplanted the teen’s genetic profile to the crotch of the pants.
  • Forensic experts did not collect underwear and penile swabs which could have further determined the provenance of the DNA on the zipper area of Holtzclaw’s pants.
  • “The misrepresentations of the DNA evidence impacted the verdicts,” they write. “A basic tenet of science is that one cannot claim the presence of a substance for which one has not tested.”

“We appreciate the Oklahoma Court of Criminal Appeals for considering our motion for leave to file the amicus brief, and we respect the Court’s decision,” add the DNA experts, in their latest letter. “However, we also respect the public’s right to know about the substance of the amicus brief.”

A local TV station, News 9, obtained some 15,000 internal emails from the Oklahoma City law enforcement community which were related to the former senior forensic scientists who testified on the case. Those emails mentioned “retesting” of the scientist’s cases, according to the report