Science & Technology


The Orange County District Attorney’ Office is committed to utilizing the latest science and technology to solve crime, exonerate the innocent, and prevent future victimization.

The OCDA Science & Technology Unit furthers these goals by harnessing and integrating cutting edge science and technology to promote justice and enhance public safety. In addition to operating the OCDA DNA Database Program, the Science and Technology Unit also administers several other programs that facilitate public safety including the OCDA Rapid DNA Program, the Red Flags Conviction Integrity Program, the Investigative Genetic Genealogy Program, and the Body Worn Camera Program.


DNA is deoxyribonucleic acid, a molecule contained in cells that gives the genetic code for life.  The DNA data that is stored in a forensic DNA database such as the OCDA DNA Database is a STR DNA profile.  A STR DNA profile consists of data from regions of DNA, called short tandem repeats (STRs), which are highly variable among individuals, allowing the information to be used for human identification.  These regions of DNA do not contain genes, thus information regarding hair color, eye color, ethnicity, and disease, among other characteristics, cannot be obtained from a STR DNA profile.

The DNA Collection Program collects DNA from mostly misdemeanor defendants who agree to provide a DNA sample as part of a negotiated case disposition.  In exchange for voluntarily consenting to provide a DNA sample, defendants are often offered a reduced charge or the chance to participate in a diversion program where the defendant has the chance to earn a complete case dismissal.  Defendants are under no obligation to accept a DA offer that includes providing a DNA sample and may seek an offer from the court.  Such court offers may or may not include providing a DNA sample for the OCDA DNA Database, at the discretion of the court. The individual offenders’ DNA samples are collected at OCDA staffed collection stations located inside each courthouse.

The Program is voluntary because the OCDA only collects DNA samples from individual who have voluntarily consented to provide a DNA sample as a term of a negotiated case disposition with either the OCDA or the Court.  The OCDA intentionally structured the DNA collection program based on knowing, voluntary consent.  All case dispositions, including those involving provision of a DNA sample, take place in the courtroom, after the 6th amendment right to counsel has attached.  Moreover, defendants complete two detailed written consent forms, one in the courtroom and another at the DNA collection station, before a DNA sample is collected.  The consent forms clearly explain the purpose of the collection and how the sample will be used.

Crime Scene DNA Profiles

Biological evidence, such as blood and saliva, collected at crime scenes is tested to develop DNA profiles.  These crime scene DNA samples are processed by the Orange County Crime Lab, and the crime scene DNA profiles are uploaded to the OCDA DNA Database.

Individual DNA Profiles

Buccal samples, collected from the cheeks of individuals as part of the OCDA DNA Collection Program, are processed by an accredited private forensic DNA lab, and the individual DNA profiles are uploaded to the OCDA DNA Database.

The Rapid DNA program aims to provide leads or pointers to law enforcement by developing DNA profiles from crime scenes in a matter of hours and searching the profiles against the OCDA DNA database.  It is available to all Orange County law enforcement agencies.  See Summary of Rapid DNA Program document for more information.