Select a language:


The Orange County Crime Laboratory (OCCL) provides all law enforcement agencies 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 140 technical and support personnel. The OCCL is equipped with state-of-the-art technology and instrumentation, and is internationally accredited by the American Society of Crime Laboratory Directors / Laboratory Accreditation Board. The OC Crime Lab is composed of five Bureaus: the Cal-ID Bureau (Automated Fingerprint Identification System), the Criminalistics Bureau, the DNA Bureau, the Identification Bureau, and the Forensic Chemistry Bureau.

Cal-ID Bureau

The Orange County Crime Laboratory Cal-ID Bureau operates and maintains the local network automated fingerprint identification system and has been serving Orange County law enforcement since 1985. In that year, the California Department of Justice began a state wide 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 in identifying the deceased. Under a Joint Agreement with the cities of Orange County, the OC Crime Lab manages the local system on behalf of all law enforcement in the County. Orange County’s AFIS is also networked with databases in several other counties, the California Department of Justice, the FBI and WIN (Western Identification Network – an eight state identification network for the western part of the United States).

Criminalistics Bureau

CSI - Scientists

The CSI – Scientist Unit forensic scientists respond to major crime scenes which are primarily homicides, officer-involved shootings and in-custody deaths. The unit provides crime scene documentation, processing, and reconstruction services for major crime scenes for county law enforcement agencies including the District Attorney’s Office. The forensic scientist may work with a local agency's Identification personnel or with the laboratory’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 call the Crime Laboratory on the more routine homicides, a forensic scientist always attends the autopsy from the case. One forensic scientist is on call during non-business hours; evenings, weekends, and holidays. The CSI unit is funded through regular division funding. Coverdell funding has been available for training and equipment purchases.

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 and tool mark evidence. 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 the submitted firearm, or may associate this evidence to a particular firearm. In addition, the unit maintains the National Integrated Ballistics Information Network (NIBIN), a searchable ATF database for cartridge cases. Cartridge cases may be entered into the database and searched to determine if the gun that fired them was used in the commission of crimes in other jurisdictions. In 2011 the FATM section had five NIBIN hits which associated firearms to multiple cases. Toolmarks are generated when two items come into contact with each other with sufficient force that one or both of them are marked. These marks may be identified or associated with a tool or a particular surface.


The Locard exchange principle states: "with contact between two items, there will be an exchange." An individual takes and leaves trace evidence behind whenever they move. The Trace unit is responsible for examining evidentiary items for this “trace” evidence and analyzing the trace evidence that is observed and collected by laboratory staff and outside submitting agencies. Trace evidence covers a wide range of analyses: explosives, fibers, fire debris (arson), glass, gunshot residue, hair, lachrymators (e.g. pepper spray), lamp filaments, paint, smokeless gunpowder and general trace unknown samples. This unit analyzes evidence items from a variety of crime types; from tampering cases (food and material items) to robberies and homicides. Evidence is analyzed using a variety of instruments and analytical techniques including microscopy. Trace evidence is used to associate victims and suspects with evidentiary items or crime scenes and to identify unknown substances.

DNA Bureau

The Orange County Crime Lab’s DNA Bureau provides body fluid identification and DNA analysis of biological samples collected at crime scenes that occur in the County of Orange. Additional services include training agencies in DNA evidence collection and preservation, entering DNA profiles into the local, state and national DNA databases, assisting the District Attorney’s Office, and providing expert witness testimony at trial. In addition to the laboratory’s ASCLD/LAB International 17025 accreditation, the section 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. Clients of the DNA Bureau include all of the law enforcement agencies in Orange County, fire agencies, the local offices of the California Highway Patrol, and agencies outside of the county who contract with the laboratory under Joint Powers Agreements.

Recent accomplishments include the implementation of new robotic technology throughout the DNA Laboratory to streamline DNA analyses, and the creation of a High Volume DNA Analysis Line. The OCCL continues to be one of the top California crime laboratories for 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 Section adds value to the criminal investigations and court proceedings in Orange County by analyzing biological material from crime scenes, identifying potential suspects through the use of the CODIS database, and providing information and scenarios that assist with crime scene reconstruction. DNA results and their interpretation are routinely provided by DNA Analysts in criminal trials and are also used during plea bargaining by the District Attorney’s Office.

Forensic Chemistry Bureau

Controlled Substances

The Controlled Substances section provides services for the identification of controlled substances from items 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.

Forensic Alcohol

The Forensic Alcohol section provides services for the detection, quantification 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 all 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.

Clandestine Laboratories

The Clandestine Laboratory Investigations Unit responds to clandestine laboratories and provides field 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 controlled substance 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.


The Toxicology section provides accurate and reliable analytical services in the detection and quantification of drugs and chemical compounds in blood, urine, tissues and 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

Latent Processing / PhotoLab / Impression Evidence

The Latent Processing Unit has a large, state of the art laboratory area and offers a full range of chemicals, powders, and fluorescent methods. The latent processing staff is highly trained in sequential latent processing techniques as well as image enhancements to ensure that all developed fingerprints are of the optimal quality for comparisons or ALPS (for automated latent fingerprint and palm print searches) entries. This unit processes evidence from a wide range of crime types including Internal Affairs Investigations to burglaries and homicides.

Various law enforcement agencies as well as those areas in the County under Sheriff’s jurisdiction request Photo Lab services. The Photo Lab unit is a full service photo laboratory which services include: scanning and printing film, printing digital images, downloading memory cards and stored images received from within the Crime Lab, other divisions of the Sheriff’s Department, and other law enforcement or governmental agencies. The photo lab also provides casework images to Sheriff’s Department Investigations, the Coroner’s office, and the Orange County District Attorney’s Office. In addition, the Photo Lab staff provides support to the CSI-Specialist program in photographing autopsies, suspects and victims of crimes, and public relations photography assignments.

The Impression Evidence Unit processes and compares shoe and tire track evidence in a wide range of cases from burglaries to homicides. Staff members actively participate in the Impression Evidence community through serving on the Scientific Working Group for Shoe Print and Tire Tread Evidence (SWGTREAD) standards committee and the International Association for Identification (IAI) sub committees. Some examiners are certified footwear examiners. The Impression Evidence section conducts comparative examinations on questioned shoe and tire track impressions found at crime scenes to known shoes or tires to determine if the questioned impressions were made by the submitted known exemplars. The section provides up-to-date technologies and current methodology to conduct these comparisons, as well as present their findings in court.

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. The Specialists are trained to perform a variety of laboratory assignments including the comparison of latent prints to submitted suspects and subject elimination prints, searching latent fingers and palm prints through the Automated Latent Fingerprint Systems (Local, DOJ, all FUAAS and IAFIS) and developing latent prints in the laboratory with the use of chemical methods. The Latent Print Unit has been working closely with the CAL-ID Unit in the acquisition of a new Automated Latent Fingerprint System which is being designed to incorporate biometric information.

The unit also assists agencies in Orange County who do not have latent fingerprint examiners on staff or have access to the automated latent fingerprint databases. They assist 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 is responsible for covering all crime scene calls in the unincorporated areas of Orange County. The unit responds to a wide range of crime scene types; from residential burglaries to homicides. In addition the unit covers all Officer Involved Shootings in the county except those that occur in the city of Huntington Beach. The unit also provides mutual aide by assisting other cities when called upon. This is usually for major crimes, but not limited to those scenes only.
From crime scenes, the unit collects and develops evidence which can be examined by other sections in the crime laboratory. This includes latent prints that are developed and lifted at the scene (Latent Print Unit), DNA swabs (DNA Unit), Firearms (Firearms Unit), evidence to be processed for latent prints (Latent Processing Unit), trace evidence (Trace Unit), and shoe and tire impressions (Shoe and Tire Impression Unit). This evidence can be used to associate or identify suspects involved in the crime(s) being investigated.

For more information visit the OC Crime Lab Website.