The Investigative Services Bureau is responsible for the investigation of criminal offenses. It functions to provide investigative, analytical and crime-victim services to the residents of Oxnard that maximize high quality, efficiency, and coordination with the criminal justice system. All efforts focus to promote the safety of the community and its residents.
The Investigative Services Bureau is overseen by an assistant chief of police, a commander, and five sergeants. This section of the Police Department is also staffed with civilian positions that provide essential support functions. Oxnard Police detectives handled approximately thirteen thousand cases in the year 2007. The bureau’s operating budget for the 2007-2008 fiscal year was $7.9 million.
The Investigative Services Bureau is comprised of detective units that fall into the following general categories: Crimes Against Persons, Property Crimes and Narcotics Investigations. Workgroups within the bureau include:
| Major Crimes Investigations (homicide) | Gang Investigations | Robbery / Aggravated Assault Investigations |
| Graffiti Investigations | Sexual Assault Investigations | Domestic Violence Investigations |
| Burglary Investigations | Fraud / Forgery Investigations | General Assignment Investigations |
| Narcotics Investigations | Crime Prevention Detail | Crime Analysis |
| Crime Scene Investigations (CSI) | Victim Services Specialist | Sex Offender Registration Specialist |
| Court Liaison Detail | Missing Persons Specialist |