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. Specialized sections of the crime laboratory identify, analyze and report on various forms of evidence such as DNA, blood spatter, trace materials, chemical compounds, firearms, tool marks and latent fingerprints.
DNA analysis provides the ability to restrict potential populations of persons to which a biological sample might belong to a much smaller subset of suspects. Such a determination is useful in identifying the source and, subsequently, connecting that source to a particular death or crime scene. 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 and 18 countries to provide a means of comparing forensic casework profiles. The database search may result in linking unsolved cases to a single perpetrator and can provide significant investigative leads.
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.
Examination and analyses of firearms, projectiles, ballistics and markings imparted by any form of tool, fall within the purview of the firearms and tool marks laboratory. Firearms submitted are examined for inherent characteristics, unique identifiers and safety related factors, and can be test-fired to obtain reference material that can be compared to submitted evidence. Range of fire determinations can be carried out on a 40-foot indoor range.
Latent fingerprint examination is a fundamental tool of the Medical Examiner’s Office, with latent prints being utilized as a scientific form of identification on unidentified bodies that come into the office. Fingerprints can also be retrieved from submitted evidence and used to assist in identifying a criminal suspect. Applying the newest technology, the latent print examiner achieves remarkable results in lifting prints from various substrates and establishing positive fingerprint comparisons.
A fully-equipped forensic photography laboratory was added to the crime lab in 1994. By 2005, the laboratory had replaced all film processing with digital photography. In addition to more traditional photography methodologies, the lab is capable of making photographs utilizing ultraviolet and infrared techniques. Image enhancement can also be performed. Pictures, enlargements and other services are provided to the medical examiner, to the courts and to individuals for educational or research-based presentations.
Dr. Howe received her Ph.D. in Toxicology from Texas A&M University. A forensic scientist since 1996, she is an active member of the American Academy of Forensic Sciences, the Society of Forensic Toxicologists, and the Texas Association of Crime Laboratory Directors. Dr. Howe has published a number of scientific articles in peer-reviewed journals in the field of molecular toxicology.
A copy of the current Laboratory Services Handbook may be downloaded using the following link:
County Telephone Operator 817-884-1111
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