SALEM, Mass. — Authorities have identified a suspect in the 1986 killing of a Massachusetts college student whose body was found in a wooded area along a highway hours after she was last seen alive.

Claire Gravel, a 20-year-old student at Salem State, went to a city pub with friends on Saturday, June 29, and was last seen alive between 1:30 a.m. and 1:45 a.m. Sunday when she was dropped off at her apartment, Essex District Attorney Jonathan Blodgett said Wednesday.

The North Andover woman’s body was found by three workers in the woods on the northbound side of Route 128 in nearby Beverly that afternoon, he said. The medical examiner determined the cause of death to be strangulation.

A grand jury on Wednesday indicted John Carey, 63, Blodgett said.

Carey is already behind bars, serving a 20-year state prison sentence for a 2008 conviction on attempted murder, home invasion and other charges.

He faces arraignment on a first-degree murder charge in Gravel’s death in Salem Superior Court at a future date. No defense attorney was listed in court records.

Carey was indicted thanks to a new lead developed by investigators in 2012 based on surviving physical evidence that underwent modern forensic testing, the district attorney’s office said.

Evidence recovered from Gravel’s clothing was instrumental in solving the case, Blodgett said, but said no more details would be released until Carey’s arraignment. He did not disclose a motive.

Blodgett said Gravel’s surviving family – her father, two brothers and a sister – were “relieved and very, very grateful” that a suspect has been identified.