During his career as a Head Deputy District Attorney in Los Angeles, Peter S. Berman oversaw the daily operations in a series of courthouses and specialized divisions, including the Hardcore Gang Division, the Sex Crimes Division, and the Career Criminal Division. He retired in 2002.

He has lectured and trained prosecutors throughout the United States for the National Prosecutors College. His work has been profiled on a number of television shows, including CBS’s Sixty Minutes.

From 2008-2018, he donated his time as a Specialist Volunteer with LAPD’s Robbery-Homicide Division, Cold Case Specials Unit, where he actively investigated unsolved homicide cases. He has been honored by the LAPD’s Robbery-Homicide Division as their 2008 Reserve Officer of the Year. In 2003, the United States Secret Service presented him with the Director's Recognition Award.