CHICAGO - A man feared to have been murdered by a serial killer has been found alive after more than three decades, officials said Wednesday.

Theodore Szal disappeared from the Chicago area in 1977 when he was 24, according to the Cook County Sheriff's office in Illinois. His race, age and the date he vanished bore similarities to the 33 victims of serial killer John Wayne Gacy, eight of whom were never identified, leading his family to believe he was dead.

On Wednesday, Cook County Sheriff Tom Dart announced Szal, 59, was found living in Beaverton, Ore.

“I believe Christmas has come early for the Szal family,” said Dart in a statement. “Being able to tell an 88-year-old father that his son, whose picture he has been carrying around for 34 years in his breast pocket, has been found alive is something special.”

Szal had decided to leave Illinois when he was 24, Dart said. He was going through a divorce, and wasn't reported missing because he had a history of dinsengaging from his family for extended periods of time, reported NBCChicago.com. But when they didn't hear from him for years, they worried he was dead.

Szal's vehicle had been found near O'Hare airport, close to Gacy's house, according to NBCChicago.com, and he had a construction-related job at the time of his disappearance, fitting the description of the killer's victims.

AP file

This 1978 file photo shows serial killer John Wayne Gacy.

The Cook County Sheriff's detectives renewed efforts in October to identify the eight unknown Gacy victims, NBCChicago.com reported. A check of Szal's name, date of birth and social security number revealed he was alive; his family was told the good news on Tuesday.

“While we are so relieved to have discovered that Ted is alive and well, our thoughts and prayers are also with the families of the victims – both known and yet to be determined – of John Wayne Gacy," Szal’s family said in a statement. "We are so thankful to Cook County Sheriff Tom Dart and Detective Jason Moran. The work they are doing is meaningful and important. With the news they were able to bring us, we do ask that our privacy be respected while we sort through the next steps with our family. Thank you."

When Szal was told his family had been searching for him, NBCChicago.com reported there was silence on the phone as a "completely surprised" Szal searched for words and said he left the area because of his divorce and a misunderstanding with the family.

This is the second time a man presumed killed by Gacy has been found alive: In late October, another former construction worker, Harold Wayne Lovell, was discovered living in Florida.

This article includes reporting by The Associated Press.