Criminalist I/II (Forensic Biology/DNA)

San Mateo County Sheriff's Office, San Mateo, CA, US


Duties may include, but are not limited to, the following:

  • Examine and identify biological fluids such as blood, saliva, and semen.
  • Perform microscopic examinations to identify biological cells.
  • Perform DNA extractions.
  • Perform quantitations of DNA extractions.
  • Perform PCR amplifications.
  • Analyze and interpret DNA typing results (including simple and complex mixtures).
  • Prepare evidence for presentation at court and testify as an expert witness on the results of laboratory analysis.
  • Engage in crime scene examination of major crime scenes; identify, document, and collect physical evidence.
  • Participate in an on-call rotation to respond to major crime scenes; approximately a one-week duration every eight weeks.
  • Take photographs.
  • Participate in public relations activities such as conducting tours of the Laboratory and speaking to various interested groups.
  • Care for and maintain laboratory equipment and instrumentation.
  • Perform related duties as assigned.


Knowledge of:

  • Current forensic methods and techniques used in the analysis and evalua¬≠tion of physical evidence likely to be used in a court case.
  • Principles of organic and inorganic chemistry, biochemistry and physiology.
  • Various types of equipment found in a forensic laboratory.
  • Courtroom procedures and testimony.
  • Recent developments, literature, and sources of information relative to criminalistics.
  • Principles of photography.

Skill/Ability to:

  • Performing physical and chemical tests commonly used in the analysis of physical evidence.
  • Using a wide variety of equipment including microscopes and cameras.
  • Understanding and carrying out detailed, highly technical oral and written instructions.
  • Communicating verbally. Writing clear, concise reports and correspondence.

Other Requirements:

  • Participate in the Laboratory's on-call, crime scene rotation schedule.
  • Pass a detailed background investigation and pre-employment medical exam prior to appointment.


$90,334.40 - $140,608.00 / Annually

How to apply

Applications for this position will only be accepted online. If you are currently on the County's website, you may click the "Apply" button. If you are not on the County's website, please go to to apply. Online applications must be received by the Human Resources Department before midnight on the final filing date.