Crime Crime History It Was the 'Ultimate Maximum Security Prison.' So How Did 3 Inmates Escape 62 Years Ago? In 1962, prisoners Frank Lee Morris, John Anglin and Clarence Anglin used paint and tape to escape "The Rock" - one of the most high-security prisons By Samira Asma-Sadeque Published on June 11, 2024 06:19PM EDT Close Clarence Anglin (left), John William Anglin, and Frank Lee. Photo: Bettmann/Getty It had earned its reputation as a “forbidding place," complete with the grandeur and build of a fort, isolated by the cold Pacific Ocean, made with tough iron bars and frequent checks by security guards. Built across the 22-acre island in the bay of San Francisco, the Alcatraz prison housed the most notorious criminals between 1934 and 1963, per the FBI. However, in the end, all it took for Alcatraz’s legacy as “The Rock” to unravel was a set of plaster and paint used by three prisoners who made dummies to evade security - pulling off the most successful escape in the prison's history. An image from Clarence Anglin's cell shows how the dummy heads were arranged to fool the guards into thinking the inmates were still asleep. U.S. Marshals On the morning of June 12, 1962, when prison security was doing their daily check on inmates, one guard came across what he initially thought was a decapitated head in the cell of Frank Lee Morris. The guard “reportedly fell back screaming when he reached through the bars to nudge the inmate's head and the likeness fell to the floor,” according to a 1991 Associated Press report from the FBI’s archive, which was obtained by PEOPLE. It was soon discovered that Morris had escaped alongside John Anglin and his brother Clarence Anglin – all three convicted bank robbers. Profile of the dummy head found in Morris' cell. The broken nose happened when the head rolled off the bed and hit the floor after a guard reached through the bars and pushed it, according to the U.S. Marshal's website. U.S. Marshals The three had planned their escape “by utilizing a homemade raft” which they crafted over about a year, according to a December 1962 government memorandum reviewed by PEOPLE. Clarence was serving 15 years in prison, Morris was serving 14 years in prison and John was serving 10 years in prison at the time of their escape. The FBI determined Morris to be “superior intelligence” with an I.Q. of 133, and alleged he was the mastermind behind the plan. Mysterious Letter Raises Possibility Trio of Alcatraz Prisoners Survived 1962 Escape, Swam to Land Alcatraz, which has since become a tourist attraction in San Francisco, was built to host not just the most dangerous criminals but especially those who had a history of escapes. Even though the Anglin brothers and Morris’ escape gained the most notoriety, they were not the only ones to attempt an escape. While most were caught, some did not survive the attempt. Against the background of that record, the trio's escape - and the subsequent failure of law enforcement to catch them - has made it one of the most infamous cases of prison break. Over the years, there have been leads that led nowhere. Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases. In 2018, local news channel KPIX 5 obtained a letter, in which the writer claimed to be John and said they "made it that night." "I'm 83 years old and in bad shape. I have cancer," read a part of the letter, which was exclusively obtained by the outlet. "Yes we all made it that night but barely!" The U.S. Marshals Service reportedly sent the letter to the FBI for an investigation but the results were inconclusive, per the outlet. In June 2022, the Marshal Service released age-progressed photos of the three escapees, who would be in their 90s by now. But so far, it appears to be yet another lead that has not answered any questions about the fate of the three men. The FBI archives were obtained by PEOPLE through Gale, an online service which includes historical items like case files, photos, notes, and unsolved investigations and are available at no cost through many libraries that use Gale.