Nassau County (N.Y.) Police Lt. Kevin Smith told ABCNews.com today that they had turned over whatever information they had on the Steven Damman case to the FBI's Detroit field office, mostly just paperwork and other documents.
"There's really no forensic or any type of evidence like that," Smith said.
Smith said his department first heard of Barnes in March, when he called to tell them he thought he might be Steven. He had done a search on the Internet of kidnapped boys that matched his age and found a striking similarity in the Damman case.
Smith said Barnes called back after Horne had consented to a private DNA test that showed a "possibility" the two were siblings. The FBI's laboratory in Quantico, Va., is now processing a second more definitive test, he said.
Sandra Berchtold, the FBI's Detroit field office spokeswoman, said she could not confirm or deny any information that does not exist in public records and that includes any information on the Damman case.
But, she said, the FBI does generally conduct investigations into kidnapping cases.
Smith said there's still a lot of speculation that Barnes is Steven Damman. While there have been few recent leads in the case, the forensic tests in 2003 officially ruled out the possibility that Steven Damman was "the boy in the box," a small child found naked in a cardboard box in Philadelphia in 1957.
Like all unsolved crimes, Smith said, "this case always has someone on it."
Ernie Allen, president and CEO of the National Center for Missing and Exploited Children, said that parents of any missing children are often consumed by not knowing what happened.
In a case like Steven Damman's, where decades pass without any answers, families often move on, Allen said, "but it never disappears from their thought process.
"The reality is you always think about that lost child," he said. "Just not knowing is what eats at you."
Though the center was not involved in Damman's disappearance as a cold case -- the center was founded in 1984 -- it has helped identify missing children for decades, one case going as far back as the 1940s.
"It's unusual," he said, of a missing child being found alive and well after so long, "but it's not unprecedented."
Allen said children Steven's age are very easily manipulated and trusting of adults.
"It's absolutely plausible that this child would have no memory of his early life," Allen said.
The area from which Steven Damman disappeared, Smith said, has undergone a "complete change" from that day in 1955. The shopping area his mother was visiting that day has been torn down to make way for a new shopping plaza.
And while the town was once flush with military families, the air base that brought in so many residents is gone. All that remains, Smith said, is some recruiter housing.
According to the Nassau County Police Department's 1955 missing poster, Jerry Damman was a first class airman who had been stationed all over the country.