Mr. Dean was a sworn law enforcement officer in both a voluntary and employed capacity for over 44 years. He began his law enforcement career in 1975 as a Volunteer Reserve Police Officer with the City of San Diego Police Department where he worked both patrol and undercover assignments.

On April 4, 1977, Mr. Dean accepted a sworn position as a Deputy Sheriff with the San Bernardino County Sheriff’s Department where he served for the next 28 years. He worked many assignments; Corrections, Patrol, Investigative, Supervisory and Administrative. During that time, he gained vast expertise in the investigation of violent crime, complex murder cases and Use of Deadly Force investigations.

Specifically, Mr. Dean spent 8 years as a Sheriff’s Homicide Sergeant where he supervised Homicide Detectives, Station Detectives, Criminalists and Crime Scene and Forensic Specialists with their investigations. During his tenure with the Sheriff’s Homicide Detail, he investigated, supervised and consulted on over 250 murder, suspicious death, in-custody death and suicide cases as well as an additional 25 Officer Involved Shootings, Use of Deadly Force and In-Custody Death cases. Mr. Dean’s homicide experience includes the investigation of Special Circumstance Death Penalty cases, 1st and 2nd degree murder cases, both Voluntary and In-Voluntary manslaughter cases, justifiable homicide, self-defense cases, and Cold Case murder investigations. Over his career Mr. Dean has investigated four Death Penalty cases and several serial killers.

In December 2004, and after Honorably retiring from the San Bernardino County Sheriff’s Department, Mr. Dean accepted a position as a Criminal Investigator with the San Diego County District Attorney’s Office. He was promoted twice and eventually retired honorably from the District Attorney’s Office after 15 years years of service on October 18, 2019 as a DA Investigator III.

At the San Diego DA’s Office, Mr. Dean was initially assigned to the Superior Court Division to conduct following up investigations and prepare major cases for trial. After less than two years in that assignment, Mr. Dean was transferred to the District Attorney’s Special Operations Unit. In that assignment, and between 2006 and 2013, Mr. Dean was the Lead DA Investigator assigned to, and responsible for investigating all Officer Involved Shootings, Law Enforcement Use of Deadly Force and In-Custody Death cases that resulted in great bodily injury or death that occurred within the County of San Diego.

For 7 years, Mr. Dean responded to, investigated, reviewed and consulted on every Officer Involved Shooting (OIS) and In-Custody Death case that occurred within the County of San Diego. During his tenure with the District Attorney’s Office, he investigated and consulted on an additional 50 homicide cases and over 125 Officer Involved shooting and In-Custody Death cases.

In 2013, Mr. Dean was assigned to the San Diego DA’s CAPO – Crimes Against Peace Officers Unit – where he was the Lead DA Investigator responsible for investigating all Crimes Committed Against Peace Officers within the County of San Diego that resulted in Great Bodily Injury or Death.

For the next 7 years Mr. Dean investigated for the DA’s Office many high profile cases including: The ambush murder of San Diego Police Officer Christopher Wilson, the attempted murder of San Diego Police Officer Tim Bell, the murder of San Diego Police Officer Jonathan DeGuzman and attempted murder of San Diego Police Officer Wade Irwin , the murder of San Diego Police Officer Jeremy Henwood, the murder of Oceanside Police Officer Dan Bessant, the vehicular manslaughter of San Diego Sheriff’s Deputy Ken Collier, and the attempted murders of San Diego Sheriff’s Detective Ali Perez and Sergeant Craig Johnson, to name a few.

Mr. Dean Honorably retired from the San Diego County District Attorney’s Office on October 18, 2019. In October of 2020, Mr. Dean obtained his Private Investigator’s License and opened Bobby Dean Investigations.