Updated

A Massachusetts woman is hoping that DNA will solve her sister’s murder nearly 40 years ago.

Theresa Corley, 19, was raped and strangled and her naked body was found on the side of a highway in Bellingham, Mass., on Dec. 4, 1978. Her family pushed to have the body exhumed in May to search for DNA evidence.

"We've always wanted to do the right thing by her," her sister Gerri Houde told Fox 25 Boston. "The people that are out there that thought we forgot about what happened to Theresa, will realize we haven't forgotten her."

Police believe Corley may have scratched her killer during the sexual assault.

Corley’s family has been told that evidence collected after the exhumation included fingernail scrapings which were sent to the lab for processing, the station reported.

The key question is whether the scrapings still contain DNA evidence despite the passage of time.

“It’s going to be very difficult to know what they can get until somebody tries,” Boston University DNA expert Robin Cotton told the station. “So the question is should you try now or should you try later.”

Cotton was a prosecution witness at the O.J. Simpson murder trial in Los Angeles.

“It all depends on how many (DNA) cells were there and what condition they are in now,” the scientist added.

Investigators said that the night she was killed Corley went to a bar with friends. She and the friends argued and she left.

The investigators said that she then went to an apartment with some others, left and started walking home.

Police found her body in a ditch off I-495 a few days later.

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