As cold cases go, this one was frozen. Forty-one years ago a young woman’s badly decomposed body was found floating under a highway overpass at the southern end of Lake Panasoffkee, in central Florida, about an hour and a half northeast of Tampa.

There was no clue to her identity, but one clear sign of her fate. “A man’s belt was wrapped around her neck,” said Darren Norris, an investigator with the Sumter County Sheriff’s office who is now in charge of the case. (The original lead investigator was William O. Farmer, who is now sheriff.)

She was pulled from the water on Feb. 19, 1971, and detectives spent thousands of hours in a futile effort to determine who she was and who might have killed her. She was buried as Jane Doe.