PORTLAND, Ore. (KOIN) — Speculation continues to swirl with people pointing to new suspects in the only unsolved skyjacking in the United States.

It’s been nearly 47 years since DB Cooper got on that plane in Portland — most of what happened next remains a mystery.

Cooper took over Northwest Orient Flight 305 out of Portland, snagging $200,000 and strapping it to his body before parachuting from the plane, never to be seen again.

“I believe that the real DB Cooper is probably on the FBI’s radar screen and has probably been there for some time,” DB Cooper researcher Eric Ulis said. 

Ulis, who lives in Arizona, has been interested in his case since he was a kid. In the past 10 years, he combed over thousands of pages of FBI note in his research.

“It’s as if we have a puzzle of 10,000 pieces and we’ve got maybe 100 or 200 of these pieces and we’re trying to figure out this all fits together,” Ulis said.

It’s something people have been trying to figure out for nearly five decades — who was, or is DB Cooper? 

“He’s still alive today,” Ulis said. “92 years old. A gentleman who’s been on the FBI radar from within one week of the highjacking.”

That man is Sheridan Peterson of California, who according to Ulis, checks all the boxes. Skydiving experience, a confidential bank account, DNA comparison and the fact that he’s refused to deny he is DB Cooper.

It’s the continued allure of the mystery that led Ulis to spearhead DBCoopercon — a conference dedicated solely to DB Cooper. The free event is coming up on November 24 at the Columbia Edgewater Country Club on NE Marine Drive. 

“People are fascinated with these things and there comes a point where the mystery of it all transcends the reality of it,” Ulis said.