Twenty-four years after he provided crucial testimony that helped send a man to Texas’s death row, DNA expert William Watson has recanted his opinion and called out Harris County prosecutors — including an assistant district attorney turned true-crime TV star — for distorting his conclusions to win a conviction.
asserted
Watson → provide → conviction
In a new court filing seeking to overturn Jeffrey Prible’s 2002 conviction for the murder of a Houston family, Watson said he would never give the same testimony today.
asserted
he → seek → testimony
“Based on … changes in the field and my own increased experience and scientific knowledge, if I were asked to testify today, my answers to many of the questions asked by the State at trial would be different,” he wrote in a declaration filed on August 28.
asserted
he → base → August
“Today I would provide more thorough and nuanced explanations.”
asserted
I → provide → explanations
Watson also wrote that prosecutors “misrepresented” his testimony in both their opening and closing statements, and made “inflammatory” remarks that twisted both the science and his opinions.
asserted
that → write → science
Prible was accused of murdering his friends Steve Herrera and Nilda Tirado, who were found shot to death at their home in North Houston in 1999.
asserted
who → accuse → 1999
A fire was started in an apparent attempt to cover up the crime; the couple’s three young children died from smoke inhalation.
asserted
children → start → inhalation
Prible had been hanging out at the couple’s home in the hours before they were killed, which made him an early suspect.
asserted
him → hang → hours
Prible had an explanation for this; as he told investigators at the time, he and Tirado had been having an affair behind Herrera’s back, and she had performed oral sex on him earlier that evening.
asserted
she → have → him
The case went cold until Harris County Assistant District Attorney Kelly Siegler took it over, reexamining the evidence and concluding that there was no innocent explanation for the presence of Prible’s DNA.
asserted
Siegler → go → DNA
Instead, Siegler decided, the semen was evidence of a brutal sexual assault that took place just seconds before Tirado was shot in the back of the head.
asserted
Tirado → decide → head
“I would suggest to you what the evidence indicates is that the Defendant after killing Steve forced Nilda to orally copulate him at gunpoint and executed her as soon as he finished,” Siegler’s co-counsel, Vic Wisner, told the jury during the state’s closing argument.
asserted
counsel → suggest → argument
“As horrific as that sounds, that is the only logical conclusion that you can draw from that evidence.”
asserted
you → sound → evidence
Siegler reiterated the claim to maximum effect: “She left this world with his penis in her mouth,” she told jurors in her closing, “hoping to God that her babies would survive the nightmare that is Jeff Prible.”
uncertain
that → reiterate → nightmare
Prible was convicted and sentenced to death in October 2002; he maintains his innocence.
asserted
he → convict → innocence
Prible’s case was at the heart of a three-part series published by The Intercept in 2023.
asserted
case → publish → 2023
The investigation explored how Siegler, who won 19 death sentences over the course of her nearly 22-year career in Houston, went on to become a true-crime celebrity in the decades after sending Prible to death row.
asserted
who → explore → row
The series also showed how her Oxygen Network true-crime reality shows — “Cold Justice,” now in its eighth season, and “Prosecuting Evil With Kelly Siegler,” starting its third season this fall — portray Siegler as a gifted crime-fighter and compassionate crusader for victims, even as she left a trail of questionable convictions in her wake.
asserted
she → show → wake
In Prible’s case, as The Intercept’s reporting showed, Siegler built her prosecution not only on questionable claims about the DNA evidence, but also on the highly dubious account of a jailhouse informant who claimed that Prible confessed to him.
uncertain
Prible → show → him
This witness, it turned out, was part of a ring of snitches who cooperated with Siegler in exchange for assistance getting their own sentences reduced.
asserted
sentences → turn → assistance
During Prible’s federal appeals, multiple members of this snitch ring testified that informants offered Siegler false evidence against Prible — and one said that Siegler actually provided him with details about the case.
asserted
Siegler → testify → case
At best, Siegler was careless about scrutinizing the information they provided.
asserted
they → scrutinize → information
At worst, as Prible’s lawyers argued to a federal district court, she actively conspired to win a conviction despite knowing the case wouldn’t otherwise hold up — framing an innocent man for murder.
asserted
case → argue → murder
In 2020, U.S. District Court Judge Keith Ellison overturned Prible’s conviction, finding that Siegler had withheld key information about her dealings with the informants from Prible’s defense.
asserted
Siegler → overturn → defense
“Without question, the prosecution in this case engaged in a pattern of deceptive behavior and active concealment.
asserted
prosecution → engage → behavior
And the evidence suppressed sufficiently serves to contravert the primary basis for Prible’s conviction,” Ellison wrote.
asserted
Ellison → suppress → conviction
“Siegler intentionally and knowingly withheld information,” he went on, and “was deceptive about her efforts to do so.”
asserted
he → withhold → efforts
Texas appealed the ruling to the 5th U.S. Circuit Court of Appeals.
asserted
Texas → appeal → Appeals
Rather than considering the evidence that Siegler had violated Prible’s constitutional rights, the court instead reinstated Prible’s conviction based solely on procedural grounds.
asserted
court → consider → grounds
In the new state court filing, Prible’s legal team, led by Austin attorney Gretchen Scardino, reupped their previous allegations while also arguing to the Texas Court of Criminal Appeals that Watson’s recent recantation further undermines Prible’s conviction.
asserted
recantation → lead → conviction
“This Court has not had the opportunity to review the trove of new evidence that came to light during the federal habeas proceedings, until now,” they wrote.
asserted
they → have → proceedings
Watson’s declaration cites “significant changes in the field of forensic biology, in the progression of the scientific methods used to analyze the evidence in Prible’s case, and in his own scientific knowledge,” they continued.
asserted
they → cite → knowledge
“This new evidence shows that Prible is actually innocent.”
asserted
Prible → show → ?
Watson first expressed misgivings about his trial testimony and the way it was weaponized in an interview with The Intercept in 2023.
asserted
it → express → 2023
His answers were more definitive than they should have been, he said, and he certainly did not intend to endorse the state’s insistence that there was “no way in the world that semen wasn’t deposited either moments before or seconds after Nilda died.”
asserted
Nilda → say → world
“‘No way in the world’ is not something I would have said,” Watson told us.
asserted
Watson → say → us
The DNA from Tirado’s mouth was one of three samples collected after the murders.
asserted
DNA → collect → murders
DNA matching Herrera, Tirado’s boyfriend, was also found on vaginal and anal swabs.
asserted
DNA → match → swabs
At Prible’s 2002 trial, Watson testified he’d never before been able to extract a male DNA profile from an oral swab, and that his understanding was that sperm wouldn’t persist in the oral cavity absent Tirado’s murder.
asserted
sperm → testify → murder
Siegler crudely emphasized these findings during her closing argument.
asserted
Siegler → emphasize → argument
…and 54 more, not listed.
