• Departments
  • Commissioners Court
  • Elected Officials
  • Courts
  • Justice of the Peace Courts
  • Constables
  • Employment Doing Business Our Community How Do i...
  • Apply For
  • Search For
  • Access
  • Pay
  • Register For
  • View
  • OpenBooks

    Criminalistics Laboratory


    Laboratory equipment

    Since 1989, the Tarrant County Medical Examiner’s District has operated a full-service crime laboratory, serving the needs of the Medical Examiner’s Office, Criminal District Attorney’s Offices and law enforcement agencies in North Central Texas and throughout the United States.  Equipped with modern analytical instrumentation, the various sections of the crime laboratory combine scientific technology with an experienced professional staff.  The criminalistics laboratory includes specialized sections of DNA, trace materials, firearms, toolmarks and latent fingerprints that examine, analyze, and report evidentiary findings.

    Forensic Biology

    DNA analysis provides the ability to test items to make comparisons between the DNA profiles obtained.  The uniqueness of a DNA profile enables the lab to not only produce positive associations between individuals and evidence, but also eliminate individuals that could not have contributed to the DNA evidence.  Additionally, the DNA laboratory is a designated CODIS (Combined DNA Index System) laboratory.  CODIS is the FBI’s DNA database that links all 50 states to provide a means of comparing forensic casework profiles.  The database search may result in linking unsolved cases and can provide significant investigative leads.

    Trace Evidence

    Trace evidence is that material which, because of its size or weight, can be transferred easily from one individual or object to another.  The Trace Evidence Laboratory provides analysis of primer gunshot residue, evaluates hair for the determination of DNA suitability, processes materials for the recovery of trace evidence and utilizes advanced instrumentation such as the scanning electron microscope coupled with an energy dispersive x-ray analysis spectrometer.  Trace analysts must be knowledgeable of relevant and scientifically-sound analytical, investigative methodologies.

    Firearms and Toolmarks

    The Firearm/Toolmark section is responsible for documenting, examining and comparing any evidence related to firearms or tools.  Using comparison microscopy, two objects are simultaneously compared to each other to determine if the toolmarks observed on them originated from the same source.  Firearm examination includes functionality testing, demonstration of operability, microscopic comparison, serial number restoration, and muzzle-to-target examinations.  Toolmark analysis includes the examination of any tool and/or toolmark.  Examples of tools are bolt cutters, screwdrivers, or knives; while toolmarks can be from any object that a tool can impart marks to, such as padlocks, cartilage, or wires.  If an object is broken into pieces, a fracture match examination can be conducted to determine if the two pieces were formerly a single unit.

    Latent Fingerprints

    At the Medical Examiner’s Office, fingerprint examination is a fundamental tool utilized as a scientific form of identification on unidentified bodies.  Fingerprints can also be developed from evidence using visual examination, specialized lighting, and chemical reagent scientific techniques.  Developed fingerprints can be compared to fingerprint records to identify the source of the impression.


    A copy of the current Laboratory Services Handbook may be downloaded using the following link:

       Lab Services Handbook
    This page was last modified on August 09, 2022


    County Telephone Operator 817-884-1111

    Tarrant County provides the information contained in this web site as a public service. Every effort is made to ensure that information provided is correct. However, in any case where legal reliance on information contained in these pages is required, the official records of Tarrant County should be consulted. Tarrant County is not responsible for the content of, nor endorses any site which has a link from the Tarrant County web site.

    This site is best experienced with supported browsers: Internet Explorer 9 and above, Google Chrome, Mozilla Firefox, or Apple Safari. If you use an older or unsupported browser, you might notice that some features do not function properly. Click the browser name above to learn more about the recommended browsers.

    County Seal

    100 E. Weatherford, Fort Worth, Texas 76196