After nearly 60 years on display, it's expected for heads to have some wear and tear, especially those used during the 1962 inmate escape from Alcatraz Federal Penitentiary. To preserve these relics of Bay Area history, the FBI and National Park Service (NPS) are turning to contemporary technology – 3-D scanning.

If you're familiar with the story – and you can hardly call yourself a San Franciscan if you're not – you know that these aren't real human heads, but papier-mache likenesses of four Alcatraz escapees. The inmates – Frank Morris, and John and Clarence Anglin – placed the noggins on their pillows (to give the appearance that they were still asleep in their beds) and fled the main prison building for freedom. They were never found – dead nor alive. Allen West, the fourth member of the group, never managed to get out of his cell.