For a number of reasons, a player could be arrested. In this case they are imprisoned until either their sentence runs out or they are pardoned by a corrupt judge. They can also be rescued. They are locked away for the first A-round after their capture in a designated "prison" area of the City. Then in the B-round, if their Family decides to attempt a rescue, this is acted out. Otherwise the prisoner takes on the role of a Civilian until he is released.
Sentences usually last two or three rounds. Repeat offences are weighted with a life sentence.
For everyday misdemeanours people are simply sent to prison without a trial. For more interesting cases, Civilian lawyers must be called in and a courtroom scene enacted in the B-round. This only happens for a really major event, like when a Don is convicted (which only happens when all the police are under pay from the other Families, or if a family is bankrupted). All the crimes the character has committed during the course of the game are read out by the Clerk of Court. A barrister employed by the accused argues his case, while a barrister employed by the other two Families prosecutes. The audience act as a Jury and decide the verdict and sentence.