NEWBURGH HEIGHTS, Ohio (WJW) — It’s a mystery investigators in Newburgh Heights have been working to solve for nearly 41 years — how exactly did Kurt Sova, a healthy 17-year-old boy, end up dying?

He went to a Halloween party on October 23, 1981 and his parents never saw him again. His body was found days later in a ravine about 500 yards away from the party.

Newburgh Heights police said the coroner could not determine his cause of death and there were no signs of foul play.

Kurt’s mother, Dorothy, who has since passed, spoke to FOX 8 in 1993. She was desperately seeking answers and trying to find out what caused his untimely death.

Police say Dorothy devoted years of time looking into her son’s death, leaving detectives pages and pages of details notes about what she found.

About three years ago, her notebook was taken out of the evidence box and read by a criminal justice professor and a dozen students at Tiffin University who analyzed evidence in the case.

They worked with police following up on information and tips.

In the past three years, Newburgh Heights police have interviewed several of the witnesses, but they say they are still not sure exactly how the teenager died.

The police chief said part of the challenges detectives face now is due to the fact, at the time of Sova’s death, officers didn’t do much of an investigation.

But he says he still hopes to one day find that missing puzzle piece and figure out how a teenager with a bright future ahead of him ended up dead in a grassy field.