On Holy Thursday, Pope Francis is heading to a maximum-security prison to wash the feet of 12 inmates — including three women and a Muslim — stressing once again that a pope must serve those on society's margins.

The Paliano detention center, located in a fortress south of Rome, is the only Italian prison dedicated to housing mafia turncoats. These "collaborators of justice" can shave time off their sentences by cooperating with anti-mafia prosecutors.

It's the third Holy Thursday that Francis has spent at a detention center, part of his longstanding emphasis on ministering to prisoners and giving them rehabilitation and hope. The Vatican says two of the 12 inmates chosen for the ceremony are serving life terms, while the others have release dates between 2019 and 2073.