Like a considerable segment of the population in California and across the United States, you undoubtedly have seen what technically are crime scene technicians in action on television programs and in films. As a result, you may have few ideas about what a crime scene technician does. You have some concept of the job description and employment duties of a crime scene technician. With that said, we provide you with a comprehensive explanation of the definition and job description of a crime scene technician.

The Essential Tasks of a Crime Scene Technician at the Incident Location

In mid- to large-size jurisdictions, a crime scene technician has a basic roster of tasks. These responsibilities are virtually the same in communities mid- to large-size communities across the United States, from Los Angeles to New York City and hundreds of cities in between. These basic tasks of a crime scene technician include:

  • Secure the crime scene, in cooperation with law enforcement personnel and the coroner’s office (in the event a death is involved in the crime).
  • Take photographs or videos of the crime scene.
  • Take photographs or videos of individual pieces of evidence at the crime scene.
  • Determine what items and evidence needs to be collected from the crime scene.
  • Collect fingerprints from the crime scene.
  • Process and analyze fingerprints collected from the crime scene.
  • Collect physical evidence from the crime scene. (Physical evidence collected from the crime scene includes any relevant physical objects that might have played some type of role in the crime. In addition, the collection of physical evidence includes blood, other bodily fluids, and other biological material at the scene.)
  • Prepare crime scene diagrams and sketches. A key type of crime scene diagram is one that is rather like a “map” of the area where the incident occurred.
  • Ensure that all evidence collected from the crime scene is appropriately secured and identified. This process is called establishing a chain of custody. A chain of custody establishes how and when evidence initially was collected and by whom. It also continues to record who is involved in the transport, analysis, or any other contact with evidence collected from the scene of a crime.
  • Make a comprehensive list of all evidence collected at the crime scene.
  • Undertake the secure transfer of collected evidence to the crime lab or evidence room (or locker) at a law enforcement center.

In smaller communities, a crime scene technician is likely to be responsible for some additional tasks as well. For example, in a smaller locale, crime scene technician might be involved with assisting in taking statements from victims and witnesses. This type of supplemental work would be secondary to the work on collecting evidence from the scene.

Additional Tasks of a Crime Scene Technician

Once evidence is collected from a crime scene, a crime scene technician has additional tasks that are included in the job description for this type of employment. These include:

  • Cataloging evidence collected from the crime scene.
  • Undertaking laboratory analysis of certain types of evidence collected from the scene of a crime. For example, a crime scene technician will analyze fingerprint evidence.
  • Determine what evidence needs to be conveyed to another lab. For example, depending on the nature of the crime, blood evidence collected from the crime scene may be sent to a recognized and approved laboratory that processes and analyzes evidence of this nature as part of a criminal investigation.
  • Coordinate the analysis of evidence collected from the crime scene with the forensic work undertaken by the coroner’s office (in the case of a suspected homicide).
  • Prepare a thorough, comprehensive report pertaining to the evidence collected from the crime scene and the analysis and evaluation performed on that evidence.

Testify in Court Proceedings

A crime scene technician oftentimes is called upon to testify in court proceedings. The four most commonplace types of court proceedings at which a crime scene technician may be called to testify include:

  • Grand jury proceedings
  • Preliminary hearing
  • Evidentiary hearing
  • Trial

Grand jury proceedings are conducted to determine if a suspect should be charged with a crime in the first place. A preliminary hearing is an initial court proceeding designed to ascertain if there exists sufficient evidence to proceed onwards towards a trial. (There need not be evidence beyond a reasonable doubt at this juncture. Rather, evidence at this stage need only be sufficient to establish probable cause that a crime has been committed and the defendant potentially committed that crime.

An evidentiary hearing is conducted when a challenge is raised as to the admissibility of evidence. Finally, the trial is the proceeding court at which a determination is made as to a defendant’s guilt.

A crime scene technician has significant responsibilities and is a vital element of the criminal justice system. What a crime scene technician does not do, however, is undertake the cleanup of the crime scene. That is a task best undertaken by an experienced crime scene cleaning company.


Emily Kil

Co-Owner of Eco Bear Biohazard Cleaning Company

Together with her husband, Emily Kil is co-owner of Eco Bear, a leading biohazard remediation company in Southern California. An experienced entrepreneur, Emily assisted in founding Eco Bear as a means of combining her business experience with her desire to provide assistance to people facing challenging circumstances. Emily regularly writes about her first-hand experiences providing services like biohazard cleanup, suicide cleanup, crime scene cleanup, unattended death cleanup, and other types of difficult remediations in homes and businesses.