CASSOPOLIS, Mich. (AP) — A judge set aside a life sentence for a man who was convicted of killing his pregnant girlfriend when they were teenagers and burying her body in southwestern Michigan.

The decision Monday by a Cass County judge means Robert Leamon, 43, will get a new sentence and a chance for parole.

“It’s just devastating,” said Cindy Slates, the sister of Rebecca Stowe, who was 15 when she disappeared from the Niles area in 1993.

Stowe was strangled and her body was found in a rural area. Leamon, who was 16 at the time of the death, was arrested in 1995 and convicted two years later.

A first-degree murder conviction in Michigan carries an automatic sentence of life in prison without the possibility of parole. But judges across the country have been revisiting so-called juvenile lifer cases since the U.S. Supreme Court said people convicted of crimes they committed as minors deserve new hearings at which many factors must be considered.

In his ruling, Judge Mark Herman noted the testimony of an expert who talked about a teen’s gradual brain development and that Leamon had suffered injuries playing football and in a motorcycle crash. The judge also pointed to Leamon’s rehabilitation in prison.

Herman said keeping the original sentence “would be the easiest and safest course.”

“To do so, however, in the court’s estimation would require that the court also ignore its oath of office and ignore an analysis and consideration of the mitigating factors,” he said.

Leamon has been in jail or prison for more than 20 years. After a new sentence on Jan. 30, it’s possible that he could instantly be eligible for parole because of credit earned in prison, said prosecutor Vic Fitz, who is seeking another no-parole life term for Leamon.

Leamon’s attorney was pleased with the judge’s decision.

“The judge’s opinion and order accurately reflects the law that children possess a diminished culpability for their actions and are capable of change. Because Mr. Leamon has changed, he is entitled to a second chance,” Sofia Nelson said.