SALT LAKE CITY (ABC4) – Months after Robby Peay disappeared, the body of an unidentified young man was buried in a grave near Moab. 

Provo police are now counting on forensic science to see whether this John Doe is Peay.

“You go on for 40 years and think, ‘well you’re never going to know,’” said Peay’s sister, Chris Skowran.

In 1982, Peay escaped from a treatment center in Salt Lake City. News reports indicated Peay “escaped … And has not been seen nor heard from since.”

His mother was worried that “something has happened to her son” and asked for help from the police and the public.

“It was a lockdown facility,” Skowran said. “We still don’t know how he got out. Him and another boy ran away together. Somehow they broke out of it. And they took off.”

The other teen was caught, but Peay was never seen again.

Over the years, Provo police investigated but ran into dead ends. In the 1990s, Peay was declared dead by the courts, and a headstone was erected in the family plot in Provo.

According to a recent search warrant requested by the police, the body of a John Doe was found in Grand County Utah in the Three Gossips area of Arches National Park on Feb. 12, 1982. The warrant claimed John Doe died from a .22 caliber bullet wound to the back of the head that transected the brain and stopped in the front of the skull.

“The facial characteristics were pretty similar to Mr. Peay but nothing could be confirmed 100%,” said Sgt. Shad Lefevre of the Provo police department.

Dental records were compared, but it was not a match.

Robby was adopted at 11 months old by Lynn and Laverne Peay of Provo. His mother had saved his hair in a baby scrapbook.

“We gave police some of that hair to have it tested to see if they can get DNA from that,” Skowran said.

The police said it did not work.

“Due to it not having a root, they couldn’t compare and couldn’t get enough off the hair to be helpful,” Lefevre said.

To this day, this John Doe’s grave remains unmarked at the Sunset Gardens Cemetery near Moab.

Years later, a dental forensic expert noticed Peay’s original dental X-rays were submitted upside down, so they corrected the records and submitted them again for analysis. The results looked promising.

“They were comparing those to the body found in Moab,” Lefevre said. “It is likely. But it can’t be 100% substantiated without DNA. “

Finding Peay’s DNA is the next step for Provo police. In the meantime, his sister is hopeful.

“It would finally give us some closure,” Skowran said. “You know, it’s been a long, long time.”

A judge recently signed an order to unseal Peay’s birth records, according to the search warrant.  They now have the name of his biological family and are searching for them in hopes of obtaining his DNA that could solve this 40-year-old mystery.