We just found out something terrifying about the inmates who escaped Alcatraz 50 years ago

It’s been over five decades since the infamous Alcatraz escape, when three inmates — brothers John and Clarence Anglin and their fellow inmate, Frank Morris — carried out their grand plan. They had chiselled a hole into the walls of the prison, and shimmied out through to the roof, leaving dummy heads made of papier-mâché and real human hair in their beds.

The three men sailed onto the San Francisco Bay with makeshift paddles and a raft made of stolen raincoats, but prison officials claimed the men had drowned, allowing Alcatraz to continue claiming that they had no escapees, though 36 have tried. However, the Anglin family is now cooperating with authorities for the first time ever, and they’re claiming that not only did the brothers escape alive, but they were alive through the ’70s and may even still be at large today.

The brothers’ nephews, 48-year-old David Widner and 54-year-old Ken Widner, are featured in a History Channel special that will soon be airing entitled Alcatraz: Search for the Truth. “This is absolutely the best actionable lead we’ve had,” Art Roderick, the retired US marshal who was lead investigator on the case for 20 years, told The Post. Roderick retired in 2008 but is still working on the case. The Anglin family didn’t speak up earlier because they were “spied on and harassed by the FBI for years,” but they want to see the case solved before the sister of the escapees, Marie Anglin Widner, passed away. They also were motivated by the presumptuous attitude of the Alcatraz officials. “[Alcatraz officials] were not willing to … say, ‘Maybe [the escapees] did make it’, ” David said, according to The Post. “That gave me the motive to prove them wrong.”

The Anglin family received Christmas cards, signed with the names of the brothers’, delivered to their mother sans postage during the three years after their escape. In the special, the brothers take the cards to Roderick, and the handwriting matches — but investigators weren’t able to figure out the exact date. A photograph, which will be revealed on the show, was also provided that may prove the brothers were alive in the ’70s. “When you work these types of cases there’s a feeling you get when stuff starts to fall into place,” Roderick says in the show. “I’m getting this feeling now.”

There was a set of bones that washed up on shore north of San Francisco the year after the escape that proved to not be a match after the DNA-testing of their older brother Alfred, though the bones could still belong to Morris, who has no relatives to test.

The evidence has rejuvenated what was thought to be a dead case, and investigators are planning to search South America for signs of the Anglins, alive or dead. There will also be a book penned by David Widener that will include further evidence — including a 2014 letter from notorious crime boss Whitey Bulger to Ken Widner, telling him that he gave the brothers advice on how to be a fugitive and how to navigate bay currents.

“He taught them that when you disappear, you have to cut all ties,” Ken says in the special. “He told me in a letter, ‘This is the mistake that I made.’ He told me, ‘These brothers undoubtedly had done exactly what I told them to do.’”

If the brothers were alive today, they would be in their mid-80s. However, Roderick is hot on the case and has lined up 10 interviews since seeing the evidence. He’s even talking with US Marshals about investigating Brazil. If they passed away, the brothers hope to get their bodies sent home to Ruskin, Florida to be buried in the family plot.

The special airs tomorrow on the History Channel at 8/7c.

(Images via Twitter.)