In 1971, a man named Dan Cooper appeared hijacked a plane, stole $200,000 and two parachutes, and disappeared into the night sky somewhere over Washington state never to be seen or heard from again. Armchair investigators have long theorized about where he may have gone, and the FBI believes this may be the case never landed from his jumpbut new evidence suggests he may have gotten away with everything – only to be caught doing the same thing just five months later.

This new evidence comes in the form of a unique parachute delivered to the FBI by the children of Richard McCoy II – a skyjacker who was caught and convicted after stealing $500,000 in 1972. McCoy has long been a popular suspect among Cooper crime enthusiasts, given the similarities between his kidnapping and the Cooper escape just months earlier, but the FBI never thought the physical descriptions of the perpetrator two matched well enough to identify McCoy to put behind bars. Well, according to Popular mechanicsHis children believe the parachute is enough evidence to close the Cooper case forever.

McCoy’s children, Rick and Chanté, provided the FBI with a modified parachute and a logbook detailing McCoy’s jumps – reportedly including jumps in Utah and Oregon that matched both McCoy’s raid and the Cooper jump. The parachute modifications are important because the parachutes provided to Cooper when he was kidnapped were modified by an FBI parachutist. If the McCoy parachute matches the Cooper modifications, the case could finally be closed.

Rick and Chanté apparently knew about the slide for some time, but kept it a secret until their parents’ deaths. The couple believed McCoy’s wife, Karen, was involved in both crimes and kept the secret until she was no longer in danger. Now the children are free to reveal what they believe is the truth: that their father is the most famous skyjacker in history.