In the spring of 2013, the Texas Legislature passed a law that was hailed as the first of its kind in the country. The law expressly allows the state’s Court of Criminal Appeals to grant a new trial in cases where the underlying forensic science is flawed.

Throughout the U.S., scandals at crime labs and the discrediting of forensic methods from arson to hair-matching to dog scents have led to legal battles over whether the defendants in such cases could have their convictions overturned. With the 2013 law, Texas lawmakers said they could.

Lawyers dubbed an appeal of this sort a “Junk Science Writ.”

“In the other 49 states without a Junk Science Writ, freeing an innocent person wrongfully convicted by faulty forensics remains an obstacle,” Mark Godsey, director of the Ohio Innocence Project, wrote at the time. This past January, a similar law took effect in California.

But now the Texas law has hit an impediment, one that illustrates a dynamic likely to reach other states as they address wrongful convictions brought about by discredited forensic science: What if a field of forensic science has not been discredited, but an individual scientist makes a mistake? What if he or she recants expert testimony years after the conviction?

On June 3, the Texas Court of Criminal Appeals — the highest court for criminal cases in the state — will examine this question through the case of Neal Robbins. Since 1999, Robbins has been serving a life sentence for the murder of his girlfriend’s 17-month-old daughter, Tristen Skye Rivet. Robbins had been left alone to take care of the toddler and when her mother returned home, she was unconscious.

At Robbins’ trial, Houston medical examiner Patricia Moore concluded that the child’s death was a homicide, brought about by asphyxiation, while Robbins and his lawyers said the girl was found unconscious and that the bruising on her body was simply evidence of efforts to resuscitate her — not signs of an attack. The jury believed the medical examiner and convicted Robbins.

Eight years later, in 2007, a friend of Robbins asked the medical examiner’s office to review the autopsy, and another medical examiner found that none of the toddler’s injuries would definitely point to homicide as the cause of death. Moore recanted, writing in a letter to prosecutors that she should have ruled the cause of death “undetermined.” A district judge called Moore’s original testimony “expert fiction calculated to attain a criminal conviction” and described Moore — who has not spoken publicly on the matter — as overworked, inexperienced and biased toward the prosecution.

This past December, the nine judges of the Court of Criminal Appeals, based on the 2013 law, voted 5-4 to grant Robbins a new trial. But three members of the majority have since retired, and as a result, the court will revisit the case with oral arguments on June 3. The three new members are former prosecutors, which worries Scott Henson, who worked on the passage of the 2013 law and has lobbied for the Innocence Project of Texas and the Texas Criminal Justice Coalition. Henson says the “speculation is that probably two of them would side with the minority and flip the vote.

Cathy Cochran, one of the members of the majority who has since retired from the court, says, “It may simply be that the three new judges want to have some additional time to think about some of these important cases, not that they would necessarily reverse the prior decisions.”

Some judges in the original minority, who opposed granting Robbins a new trial, resented the idea that the Legislature should get involved at all. Judge Lawrence Meyers referred to the 2013 law as “the Legislature’s intrusion on our authority” and a “power grab.” Others said the law didn’t apply to Robbins’ case because Moore’s scientific field — autopsies — was never in question, only her individual work. Following the arguments of the prosecutors in Robbins’ case, Judge Michael Keasler wrote that the law’s “legislative history suggests that its aim is to provide an avenue of relief on science or scientific methodology subsequently found to be unsound, not an individual expert’s changed testimony.”

Responding to that interpretation, Amanda Marzullo, policy director for the Texas Defender Service, as well as Henson and other advocates, encouraged the Legislature to pass a bill saying the law does apply when an expert’s opinion has changed, as it has in Robbins’ case. The bill passed on May 25, and the deadline for Gov. Greg Abbott to sign it is June 21. Marzullo says that “whether or not Abbott signs it,” passing the bill at all may help Robbins win a new trial when his case is discussed by the Court of Criminal Appeals on June 3.

Henson, who has followed criminal justice legislation in Texas for years, says he has “never seen anything quite like” this back-and-forth between the court and the Legislature. “It’s on such a different, weird axis of conflict. It’s not partisan — it’s a pure power thing,” he says. He has written on his blog, Grits for Breakfast, that “the Legislature and the court are in essence engaged in a race between two branches of government to see who can define the scope of Texas’ new junk science writ going forward.”

It is far too soon to know how the court’s decision about the scope of the law will affect efforts to pass similar laws in other states, but the Robbins decision will certainly come to bear on other high-profile cases in Texas. The Court of Criminal Appeals will soon be tasked with ruling on the case of four women from San Antonio convicted in the 1990s of sexually molesting two young girls. Their convictions were based in part on the testimony of a pediatrician who said she saw signs of sexual abuse when she examined the victims, but has since said that her findings, if she had made them today, would be inconclusive.

“In my estimation, the stakes couldn’t be higher,” Robbins’ lawyer Brian Wice told the court last year. ”Forensic pathologists” have become “the high priests of the courtroom…Those are the people to whom the jury turns for truth.”

This story was written by Maurice Chammah for The Marshall Project, a nonprofit news organization that covers the U.S. criminal justice system. Sign up for their newsletter, or follow The Marshall Project on Facebook or Twitter.

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