A Pennsylvania judge has overturned the convictions of three men imprisoned for decades in the 1997 slaying of a 70-year-old woman even though their DNA never matched that found at the scene, but they will remain in prison while a prosecutor decides whether to appeal.

The Delaware County judge on Thursday ordered new trials for Derrick Chappell — who was 15 when he was arrested — and first cousins Morton Johnson and Sam Grasty.

“This case never should have been prosecuted. These guys never should have been charged. The evidence always was that they were innocent,” Paul Casteleiro, Grasty’s lawyer and legal director of the nonprofit Centurion, said Friday. The prosecutors, he said, “just ran roughshod” over the defendants.

The three were charged and convicted in the death of Henrietta Nickens of Chester, who told her daughter in her last known phone call that she was about to watch the 11 p.m. news. She was later found badly beaten, with her underwear removed, and her home ransacked, with blood on the walls and bedding.

The three defendants — all young people from the neighborhood — were convicted even though DNA testing at the time showed that semen found in the victim’s body and on a jacket at the scene did not match any of them, Casteleiro said.

He called the prosecution’s various theories of the case “preposterous.” To explain the lack of a DNA match, he said, they argued that the victim perhaps had consensual sex before the slaying, or that the three defendants brought a used condom to the scene, he said. Yet Nickens was chronically ill and had no known male partners, he continued.

“They just ran this absurd story and got juries to buy it,” Casteleiro said.

Common Pleas Court Judge Mary Alice Brennan at a hearing Thursday threw out the convictions and set a May 23 bail hearing to determine if county prosecutors will seek a new trial.

District Attorney Jack Stollsteimer plans to review the case next week before making a decision, a spokesperson said Friday.

Calls to lawyers for Johnson and Chappell were not immediately returned Friday. The Pennsylvania Innocence Project also worked on the case.

The men are now in their 40s. All three filed pro se petitions in federal court over the years saying they were wrongly convicted, but the petitions were denied.