The term "fiscal de pena" is a neologism (=newly coined phrase) that can be used when translating "probation officer" into Portuguese. In Brazil, there is no such thing as a probation officer. An offender who is released into the community under supervision instead of going to prison must appear before the judge on the dates determined by court to demonstrate that he or she is duly complying with all the obligations imposed by the judge.
a person whose job is to supervise criminal defendants released into the community under supervision instead of going to prison
If released early he will be supervised by probation officers.