It's one of the Northwest's most enduring mysteries - the disappearance of hijacker DBCooper during 1971 Portland to Seattle flight.
I knew he did it, it wasn't speculation, I was there when he pulled into the driveway, said Marla Cooper, who claims her uncle LD Cooper is DB Cooper.
She says he was badly injured the morning after the hijacking. Her father told her never to speak of what she saw and heard in Sisters, or that Thanksgiving morning.
However, about a year ago she took her story to the FBI along with some of her late uncle's personal items.
On Wednesday, she claims the agent in charge of the case told her they hoped to match fingerprints from her uncles toothbrush to prints lifted from the hijacked 727.
Regardless of the findings of the fingerprints, he told me the case was closing because they were certain my uncle did it, said Cooper who now lives in Oklahoma City, but is in the Portland area this week visiting family.
FBI officials admit they're testing personal items from LD Cooper, but say the case is not closed and won't comment on the future of the case.
The FBI has called Marla Cooper a credible witness.
Last week she spoke at a DB Cooper symposium on the 40th anniversary of the famous hijacking.She's working on a book about her uncle who died 12 years ago and is buried in Sisters.