They included 10 Italians, an Albanian and a prisoner from the pope's native Argentina who had written to him.
"I believe that we have a situation in which we Europeans have to unite and take the issue of security very seriously", Jose de Laoz, a businessman from Spain, said while the security sweeps were conducted near the Colosseum. Yet, he said, "the boss is Jesus".
The Pope said that although the Pope is the head of the earthly Church, the true head of the Church is Jesus: "The Pope is only the figure of Jesus and I would like to do the same that he did and the priest washes the feet of his faithful".
Speaking during the Mass, the Pope said this about Jesus Christ: "He came into this world to serve, to serve us".
The jail's inmates include some 50 former mafiosi who made deals to provide anti-mafia prosecutors with information in exchange for shorter prison sentences, along with other informers, according to the chaplain.
Pope Francis visited the maximum security facility of Paliano prison in the south of Rome.
Pope Francis has now spent three Maundy Thursdays at a detention centre. 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. "Because this is love, it's like washing the feet". Francis also visited two other inmates now in solitary confinement, according to the Associated Press.
In 2015 he once again went to a prison on the outskirts of Rome, Rebibbia, where he washed the feet of 12 inmates, men and women, from Nigeria, Congo, Ecuador, Brazil, and Italy - as well as one toddler. "This is Jesus" mandate for all of us, but especially the bishop who is father of everyone'".
They prepared gifts for the Pope including cakes, several products grown in their organic garden, olive wood artifacts and a cloak of white wool.
Francis opened the most solemn period of the Catholic Church's liturgical calendar by celebrating Mass on Thursday morning in St. Peter's Basilica before heading to Paliano.
Talking about prisoners, the pope said "Some say: "They are guilty, '" the pope said".
As someone who promptly responded to the angel's announcement by going to visit her cousin Elizabeth, Mary helps us overcome fear and "the temptation to keep ourselves from being filled to the brim, the temptation to a faint-heartedness that holds us back from going forth to fill others with joy".
On Friday, he will participate in the liturgy marking the Lord's Passion in St. Peter's Basilica.
After the 90-minute-long procession ended, Francis, in a quiet voice, read a prayer he composed that alternated expressing shame for humanity's failings and hope that "hardened hearts" will become capable of forgiving and loving. Later in the day he'll lead the torch-lit Way of the Cross at Rome's Colosseum.
On Saturday, the pontiff will take part in an evening Easter vigil in St Peter's Basilica, before celebrating Easter mass on Sunday and pronouncing the traditional "Urbi et Orbi" blessing to Rome and the world.