The body of an 18-year-old man missing since Monday was found Wednesday afternoon near South Oyster Bay Road in Hicksville, Nassau police and a relative said.
A preliminary investigation into the death of Kieran Walsh, of Hicksville, found no signs of criminality, police said.
Walsh, who Nassau police said suffered from a mental illness, was last seen just after midnight Monday, officials said. He would have turned 19 in one week, police said.
The man's cousin, Owen Steele of Smithtown, said that at about 3:30 p.m. Wednesday, he found Walsh's body near "laying down in a walkway that goes to a field behind" a Days Inn on South Oyster Bay Road.
Steele said the discovery of his cousin came at the end of a search that he began more than 12 hours before by retracing a routine Walsh maintained for two years -- walking nightly from his Prince Street home to a CVS close by on South Oyster Bay Road.
Walsh could often be seen with a can of iced tea perched on a curb outside the drugstore, Steele said.
Walsh was diagnosed with paranoid schizophrenia in 2014 after he began hearing voices and started believing people were following him, according to Steele, who said he is a retired NYPD detective.
"This is a kid who I vacationed with countless summers on the Jersey Shore -- he showed zero symptoms of anything like that, and then just all of a sudden," Steele said Wednesday night.
Walsh came from a close knit family, and lived with his mother, his older sister and two older brothers, Steele said. At 6 feet 4 inches tall, he was a gentle giant, Steele said, adding that he was quiet and respectful.
"I did the job 24 years -- it's different when you find someone who you know that well," Steele said. "It's just been devastating, devastating."