Task: Question Answering
Input (English): Passage: Pontius Pilate offers to release either Jesus of Nazareth or Barabbas, in keeping with the Passover custom. The crowd gathered for the pardoning chooses Barabbas, and Jesus is condemned to crucifixion. Returning to his friends, Barabbas asks for his lover, Rachel. His friends inform him that Rachel has become a follower of Christ. Rachel soon returns, but she is not happy to see Barabbas.
Barabbas witnesses the crucifixion of Jesus. As Jesus dies, the sky turns black, and Barabbas is shaken. He watches Christ's body sealed in the tomb. On the third morning, Barabbas finds the tomb open. Rachel tells him that Christ has risen, but Barabbas says it is an illusion, or that His followers have stolen the body. He visits the apostles; they do not know where He is, but also believe He is risen.
Rachel preaches in Jerusalem about the Christ. She is stoned to death at the insistence of the priests. Barabbas returns to his criminal ways and robs a caravan transporting several of the priests. He throws stones at one of them rather than fleeing, and is captured by Roman soldiers. The law forbids Pilate from executing someone who has been pardoned, so he sentences Barabbas to lifelong slavery in the sulfur mines of Sicily.
Barabbas survives this hellish existence for the next twenty years.  He is chained to Sahak, a sailor who was sent to the mines for allowing slaves to escape. Sahak is a Christian. Sahak at first hates Barabbas for being pardoned instead of "the Master", but the two men eventually become friends. Over time, Sahak becomes too weak to work. As the guards are about to kill him the mine is destroyed in an earthquake. Sahak and Barabbas are the only survivors. Julia, the superstitious wife of the local prefect, considers them blessed. The prefect is due to leave for Rome to be appointed to the Senate. Julia insists that Barabbas and Sahak accompany him for good luck. 
Question: What is the last name of the person who sentences someone to lifelong slavery?
Output (English): Pilate.