Forensic Services

The Forensic Services Unit is part of the Sheriff’s Operations and Support Bureau and provides comprehensive forensic support to criminal investigations and judicial proceedings in Fresno County. Forensic Services integrates laboratory analysis, crime scene response, and secure evidence management to ensure physical evidence is properly identified, collected, analyzed, preserved, and presented in court.

Our Crime Lab element, led by Supervising Criminalist Robert Benavides, is staffed by specially trained Criminalists and provides scientific examinations of physical evidence using established forensic methodologies. Since 1972, our laboratory has delivered timely, accurate, and objective results to law enforcement agencies and the courts. 

Our forensic disciplines include: 

DNA / Forensic Biology: analyzing biological evidence to identify or exclude individuals associated with criminal activity. Evidence examined may include blood, saliva, semen, skin cells, and other biological materials.

Firearms and Toolmark Examination: examining firearms-related evidence to determine whether a firearm discharged a particular bullet or cartridge case, to assess firearm function, and to assist in shooting incident reconstruction.

Controlled Substances Analysis: analyzing suspected illegal drugs to determine their chemical composition and identity. Laboratory reports provide scientifically validated results used in criminal prosecutions.

Crime Scene Reconstruction Assistance: scientific interpretation of physical evidence, scene documentation, and investigative findings to understand the sequence of events associated with a crime. This work is performed collaboratively by our Crime Lab and Crime Scene elements alongside our lead investigators.

Quality and Professional Standards: maintaining rigorous quality assurance standards, ongoing training, and proficiency testing to ensure reliable and defensible results.

Our Crime Scene element, supervised by Sergeant Scott Schwamb, is staffed by specially trained Crime Scene Specialists who provide 24-hour response to major incidents in Fresno County.

Since the appointment of its first crime scene expert in 1913, our Crime Scene element has become responsible for identifying, documenting, collecting, and preserving physical evidence at crime scenes. We specialize in latent fingerprint processing, impression evidence documentation, serial number restoration, forensic photography, detailed scene diagrams, ballistic evidence analysis, and collection of biological evidence for laboratory testing. We also provide forensic video and electronic services.

Our Crime Scene Specialists deliver forensic support to allied agencies and routinely provide expert courtroom testimony regarding evidence collection procedures and findings.

Our Property and Evidence element, supervised by Sergeant Scott Schwamb, is staffed by specially trained Property and Evidence Technicians who manage the intake, documentation, secure storage, preservation, and lawful disposition of all property and evidence collected by the Sheriff’s Office.

We safeguard the integrity of evidence by adhering to strict chain-of-custody protocols and maintaining detailed records, while managing an extensive inventory of controlled substances, firearms, and all forms of evidentiary property.

In 2026, the Sheriff’s Office established a new centralized evidence facility, consolidating operations while enhancing security, efficiency, and accountability.