He was a commander of detectives in the Chicago Police Department and the president of New York City's Citizens Crime Commission for over 25 years.
His mother was a secretary for the Chicago Police Department and his father was a saloonkeeper who spent time in prison for a variety of criminal activities.
In 1971 he moved to be a professor at New York City's John Jay College of Criminal Justice; he eventually served as dean and vice president of the school.
[4][better source needed] In 1979, Reppetto was approached by a group of businessmen who formed the nonpartisan New York City's Citizens Crime Commission.
[6] He advised New York City mayors on how to reduce crime, pointing to many historical mistakes which led to public distrust and unrest of police officers.