In 1980, the case was put in the spotlight once again, after a young boy found $5,800 in $20 bills from the ransom money decomposing along the banks of the Columbia River.
According to Marla Cooper, two conversations with her parents initially made her suspicious. The first was in 1995 with her father just before he died.
"My father made a comment about his long lost brother, uncle L.D. And said he thought he was still alive but hiding from the FBI, and I questioned why he would be hiding … he said don't you remember he hijacked that airplane?" she said.
At the time she was unable to embrace such an incredible story. But in 2009 it came up again while speaking with her mother.
"A couple years ago my mother made a comment, another comment, a similar comment that she had always suspected that my uncle L.D. was the real D.B. Cooper," she said.
She said that her uncle was obsessed with the Canadian comic book hero Dan Cooper, and even had one of the comic books thumb-tacked to the wall. She added that she thinks her uncle didn't expect to survive the hijacking.
The FBI also obtained a partial DNA sample from the black JCPenney clip-on tie Cooper left on the plane before jumping out. The FBI extracted the sample in 2001.
FBI spokesman Fred Gutt told the Seattle Times Monday that little contradictory information has emerged that would rule out the possible suspect. The FBI has determined a guitar strap that belonged to the man is not conducive to lifting fingerprints. But the case agent is trying to obtain other items with better surfaces to lift fingerprints, Gutt said. Gutt said Wednesday the case isn't a high priority, but the information can't be ignored.