Testimony turned to the world of science Friday in the trial of Antonio Cochran, the man accused of abducting and killing Zoe Hastings in 2015.

But if jurors were looking for CSI certainty, they weren’t getting it. Expert after expert testified Friday about hair and DNA evidence collected in the sexual assault exam, but none of them could conclusively say it belonged to Cochran.

Cochran, 36, is accused of kidnapping Hastings as she attempted to return a movie at a Lake Highlands pharmacy in October 2015. Prosecutors contend he was the man witnesses saw argue with Hastings and then push her into the family’s minivan. She was found stabbed in the neck the next morning in a Lake Highlands creek.

The Dallas County District Attorney's office originally planned to seek the death penalty. However, in November, the DA's office announced it would reverse the decision and instead seek life imprisonment after it was discovered Cochran has an intellectual disability, which means an IQ under 70. It's against the law to execute anyone with an intellectual disability.

Hastings’ parents listened intently in court as an expert testified about mitochondrial testing conducted on several hairs collected from the crime scene. That is a type of testing of DNA passed down through the maternal lineage.

Gloria Dimick, a forensic analyst at Mitotyping Technologies, conducted that testing. She testified that about 99.6 of the population could be excluded from hair found in Hastings’ left hand. Cochran was not among those who could be excluded. Dimick testified that the testing cannot determine for a fact that hair belongs to a specific person.

Under questioning from lead defense attorney Paul Johnson, Dimick said she had about 95 percent confidence in the scene.

“How much confidence does it take to send a man to penitentiary for life?” Johnson asked her, prompting an objection from the prosecution.

Katherine McKinney, a forensic analysis at the Texas Department of Public Safety’s lab, testified that Cochran and his paternal line could not be excluded as contributors of male DNA found on anal and vaginal swabs collected. But again, the science would not allow her to say for a certainty that the DNA belonged to Cochran.

It was clear that from Friday’s testimony that the case is likely to largely hinge on Cochran’s DNA having been found on the handle of the murder weapon. Defense attorneys have said they have a plausible explanation for why his DNA would be there.

On Friday, jurors also heard from Gary Whitman, one of two men who claimed to have witness Hastings’ abduction.

Whitman, 57, was homeless at the time of the kidnapping and living in the area.

He says he saw a man approaching Hastings “like he was on a mission.”

“It looked like she was trying to get away,” Whitman said. “It wasn’t a major struggle. He got up behind her, and he was blocking her from getting away.”

He said he saw the man reach into his pocket and point an object at Hastings, who then got in the car and left with the man.

Whitman told jurors that he ran across the busy street but lost sight of them. He said he went into a convenience store and told the clerk to call 911. He says he was wanted on an arrest warrant at the time and didn’t want to come in contact with the police.

Later, after Whitman was taken into custody on that warrant, he said he saw news coverage of Cochran’s arrest. He said he recognized Cochran’s walk as that of the man who kidnapped Hastings, but he acknowledged to jurors that he had not seen the man’s face.

Defense attorney Paul Johnson picked apart Whitman’s testimony, pointing out the inconsistencies on what he claimed he saw. Johnson questioned Whitman about telling a detective that he had been using meth at the time. From the stand, he denied that he was using meth at that time.

Johnson questioned why Whitman had come forward, telling him, “You’re record is longer than my arm.”

Whitman acknowledged from the stand that he was wanted on an arrest warrant. He was taken into custody moments after his custody concluded but outside of the presence of the jury.

The trial resumes Tuesday.