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The Orange County Crime Laboratory (OCCL) provides all law enforcement agencies in Orange County, California, with forensic evidence examination and crime scene response services to recognize, collect, and evaluate physical evidence from criminal investigations. The OCCL has grown from a one-man operation in 1948 to its present-day staff of 160 technical and support personnel. The OCCL is equipped with state-of-the-art technology and instrumentation and is an ISO/IEC 17025:2017 accredited testing and calibration laboratory (ANAB). The OCCL is composed of five Bureaus: Cal-ID (Automated Fingerprint Identification System), Criminalistics, DNA, Identification, and Forensic Chemistry.

Cal-ID Bureau

The Cal-ID Bureau operates and maintains the local network automated biometric identification system and has been serving Orange County law enforcement since 1985. In that year, the California Department of Justice began a statewide California Identification Network (Cal-ID) to provide Automated Fingerprint Identification Systems (AFIS) to law enforcement. AFIS systems were established in a county or shared between counties to provide local automated fingerprint identification of subjects booked into jails, to identify suspects in criminal cases when their latent fingerprints were left at crime scenes, and to assist the Coroner’s Office in identifying the deceased. Under a Joint Agreement with the cities of Orange County, the OCCL manages the local system on behalf of all law enforcement in the County. Orange County’s AFIS is also networked with databases at the California Department of Justice and the FBI.

Criminalistics Bureau

Firearms / Toolmarks

The Firearms/Toolmark (FATM) Unit is responsible for examining firearms and firearm related evidence such as cartridge cases, bullets and projectiles collected at crime scenes. Evidence is submitted by laboratory staff and outside agencies. This unit analyzes evidence items from a variety of crime types involving firearms; from robberies and assaults to homicides and officer involved shootings. Firearms are examined for proper function and test fired cartridge cases and bullets are generated for comparison purposes. Cartridge cases, bullets and projectiles from crime scenes are compared microscopically to known test fired cartridge cases and bullets. An examination may result in a positive conclusion that a bullet/projectile or cartridge case was fired from a submitted firearm, or the evidence may be associated to a particular firearm. In addition, the unit maintains the Orange County Ballistics Using Local Law-enforcement 3D Technology (OCBULL3T) system, a searchable database for cartridge cases and bullets/projectiles. Cartridge cases and bullets/projectiles may be entered into the database and searched to determine if the gun that fired them was used in the commission of crimes within Orange County.

Seized Drugs

The primary responsibility of the Seized Drugs Unit is the identification of seized drugs submitted by law enforcement agencies. The unit’s clandestine laboratory investigations team provides field, analysis and consultation services to law enforcement agencies that encounter clandestine drug laboratories.

Clandestine Laboratory

The Clandestine Laboratory Investigations Unit responds to clandestine laboratories and provides field, analysis and consultation services to law enforcement agencies that encounter clandestine drug laboratories. The members of this specialized unit assist law enforcement agencies in the documentation and processing of clandestine laboratory scenes for evidence of manufacturing. In addition, they also analyze clandestine laboratory samples collected from these scenes. The scenes can be very hazardous due to the unknown nature of the chemicals used and what is being manufactured.

CSI - Scientists

The CSI – Scientist Unit is a specialized team of forensic scientists that respond to major crime scenes which are primarily homicides, officer-involved shootings, and in-custody deaths. The unit provides crime scene documentation, processing, and evidence collection services for major crime scenes for law enforcement agencies including the District Attorney’s Office. The unit may work with a local agency's crime scene personnel or with personnel from the OCCL’s Identification Bureau. The forensic scientist also serves as the case liaison for follow-up laboratory examinations that may be needed in a case. While some police agencies do not request for OCCL response on the more routine homicides, a forensic scientist always attends the autopsies from these cases. One forensic scientist is on call during non-business hours, evenings, weekends, and holidays.


Currently, the Trace Evidence Unit analyzes ignitable liquids (pre- and post- fire) and fire debris for cases of alleged arson. Analysts assigned to this unit examine trace amounts of physical evidence from criminal investigations, an analysis based largely on the Locard Exchange Principle.

DNA Bureau

The OCCL’s DNA Bureau provides examination and DNA analysis of biological evidence collected from sexual assault kits and from crime scenes that occur in the County of Orange. The bureau utilizes the latest technology in DNA analysis including robotic processing procedures, autosomal and male specific DNA typing, and probabilistic genotyping to provide comprehensive, high-quality results. The highly trained Forensic Scientists within the bureau provide timely analytical results, expert witness testimony at trial, training in DNA evidence collection and preservation to law enforcement agencies, and information that assists with crime scene reconstruction and interpretation.

In addition to the laboratory’s ANAB ISO/IEC 17025:2017 testing accreditation, the bureau also follows the FBI Quality Assurance Standards as mandated by the DNA Identification Act of 1994 and submits to biannual external audits based on the FBI’s Standards.

The results and interpretation from the analysis of biological evidence are a routine part of criminal investigations and are utilized to identify potential suspects using local, state, and national DNA databases (CODIS). The OCCL continues to be one of the top California crime laboratories with regards to the number of DNA profiles entered into and searched against the State CODIS database as well as for the number of DNA database hits obtained.

The DNA Bureau provides services to all law enforcement agencies in Orange County, fire agencies, and the local offices of the California Highway Patrol.

Forensic Chemistry Bureau

Forensic Alcohol

The Forensic Alcohol section provides services for the detection, quantitation, and interpretation of forensic alcohol results to aid the criminal justice system. The blood alcohol subsection provides accurate and reliable ethanol and volatiles analysis of blood, urine, tissues, and suspect liquids. Additionally, the breath alcohol program calibrates, maintains, and trains all operators on Portable Evidential Breath Alcohol Testing (PEBT) instruments used within Orange County. The team provides scientifically sound expert testimony on the interpretation of alcohol levels and the resulting impairment as it relates to safely operating a motor vehicle.


The Toxicology section provides accurate and reliable analytical services in the detection and quantitation of drugs and chemical compounds in blood, urine, tissues, and other biological samples. These samples include evidence collected in 11550 Health and Safety violations, driving under the influence (DUI) charges, Drug Facilitated Sexual Assault and Coroner investigations. Additionally, the section provides testimony and interpretation into how drugs (including illicit compounds, prescription drugs and over-the-counter medications) can affect an individual’s ability to operate a motor vehicle safely, impairments associated with particular drug classifications and how the concentration(s) of a drug or combination of drugs can contribute to or cause death.

Identification Bureau

Photo Lab

The photo lab provides imaging services, both digital and traditional, for the Sheriff’s Department, as well as our regional law enforcement partners. The photo lab oversees the EPI photo management system, which allows digital images to be rapidly accessed by deputies, investigators, and court personnel. Our team utilizes a digital management system to manage workflow and add further levels of security and authentication to the digital images that are created. With our state-of-the-art studio the photo lab can accomplish a wide variety of photographic assignments from evidence to portraiture.

Latent processing

Specialists in the latent processing section conduct examinations of evidence in a laboratory setting to locate fingerprint ridge detail on items of evidence submitted to the crime lab.  The latent processing section utilizes over twenty different methods to develop and detect fingerprint ridge detail. The laboratory environment is best suited for these techniques, which can take several days to complete and may involve numerous sequential processing steps. Specialists in this section are highly skilled and are responsible for conducting examinations on thousands of evidence items every year with crimes ranging from burglary to homicide.  Each specialist is annually tested for proficiency and provides expert witness testimony related to the detection and processing of latent prints, based on sound scientific analysis and protocol.  This service is provided not only to the Sheriff’s Department but to all our regional law enforcement partners.

Impression Evidence

The OCCL has the only impression evidence examiners in Orange County, and we are proud to be able to provide this service not only to the Sheriff’s Department but to all the law enforcement agencies in the county. Impression evidence examiners compare shoe prints and tire tracks recovered at crime scenes to known tire or footwear samples submitted for comparison, potentially linking suspects to the scene of the crime. The impression evidence section has a footwear database that can be searched to locate the make and model of unknown shoe impressions left behind at crime scenes which is a valuable investigative tool. The staff members assigned to this section are highly trained and knowledgeable and adhere to the strict standards set forth by our accrediting body.

Latent Print Comparison Unit

The Latent Print Unit examines all latent prints collected from crime scenes, latent prints developed in the laboratory, and evidentiary latent prints submitted by agencies in Orange County. Forensic Specialists in this unit are trained to perform a variety of laboratory assignments including the comparison and verification of latent prints and inked prints to submitted suspect and subject elimination prints, searching latent finger and palm prints through the Automated Fingerprint Identification Systems (Local, DOJ, all FUAAS and IAFIS), prepare detailed reports, and testify in court. The unit also assists agencies in Orange County who do not have latent fingerprint examiners on staff or those that do not have access to the automated fingerprint identification systems. This unit assists the District Attorney’s Office with “Question of Identity” cases to confirm identification or elimination of questioned individuals and assist the Coroner’s Office in the identification of John and Jane Doe’s.

CSI – Specialists

The CSI Specialist unit provides crime scene investigation services for 13 contract cities as well as the unincorporated areas of Orange County and can provide mutual aid to other municipalities when requested. The unit can respond to a wide range of crime scenes; from simple burglaries to more complex crimes against persons, including suspicious deaths, homicides, and mass-casualty events. The team also responds to all officer involved shootings that occur within the county. Investigative services include photographic and 3-D digital scene documentation (scanning), latent print processing, and physical evidence collection. Physical evidence that is collected on-scene can be brought back to the laboratory, and further examined by other sections of the OCCL.