During the time of Don Bosco, there were four prisons in Turin. Fr. Cafasso served all of them. He would visit the convicts frequently to hear their confessions, teach them catechism, and celebrate Mass for them.
Fr. Cafasso used to send some of his student-priests to help him out in this undertaking. Initially, Don Bosco would not want to help in the assignment. The wretched appearance of the prisoners and the gloominess of the place he couldn't take. However, because of his love for souls and his friendship with Fr. Cafasso propelled him to put forth his little contribution in this endeavor.
At first, it was a losing battle. He found it hard to make the convicts actively participate in the catechesis. But through his hard work and perseverance, he achieved to gain the trust of many of them, and thus, led them back to the Christian life.
The prisoners must have felt Don Bosco's genuine concern for their welfare that they would open up things to him. He wrote "Little by little, I instilled in them self respect, and made them understand the reasonableness of earning one's daily bread by honest toil and not by thievery."
In his frequent visit to the prisoners, he learned precious lessons he would later on find useful for his educational apostolate.