Created by the Texas Legislature in 2005, the commission — made up of seven scientists, one prosecutor and one defense attorney — does not investigate the guilt or innocence of defendants, but rather the reliability and integrity of the forensic science used to win their convictions. Earlier this year, its inquiry into the Bryan case broadened into a re-examination of bloodstain-pattern analysis, a forensic discipline whose practitioners regard the drops, spatters and trails of blood at a crime scene as clues that can sometimes be used to reverse-engineer the crime itself.

The commission examined the training of some of the discipline’s practitioners, who have been admitted as expert witnesses in courts around the country despite having completed no more than a weeklong course in bloodstain interpretation.

Robert Thorman, a police detective from Harker Heights, Tex., with 40 hours of training in bloodstain-pattern analysis, was a key prosecution witness in the Bryan case. His testimony about a blood-speckled flashlight found by the victim’s brother in the trunk of Mr. Bryan’s car four days after the murder was the linchpin of the prosecution’s case.

Yet what connection the flashlight had to the crime, if any, was never clear. In 1985, a crime lab technician working before the advent of DNA analysis determined the blood on the flashlight to be type O, which corresponded not only to Mr. Bryan’s wife, Mickey, but also to nearly half the population.

To secure a guilty verdict, prosecutors needed to tie the flashlight to the crime scene. Based on his assessment of photographs of the flashlight, Mr. Thorman testified that the flecks of blood on its lens were “back spatter” — a pattern that indicated a close-range shooting. With the help of prosecutors, he wove a narrative that suggested the flashlight had been present at the crime scene — specifically, that the killer was holding the flashlight in one hand at the time that he shot Mickey Bryan.