ABSTRACT
The Harris County (Houston, Texas) Institute of Forensic Sciences began to send, on occasion, a trace evidence analyst to homicide scenes in the early 2000s. Crime lab analysts from the trace evidence section collected trace tape lifts from the decedent in search of foreign hairs, fibers, and other trace evidence that might link a perpetrator to the crime. It soon became apparent that traditional trace evidence rarely contributed to investigations. Even when a suspect was known, trace evidence seldom linked the individual to the crime. In the best of circumstances, comparisons led to matching class characteristics. Occasional associations, but not identifications, resulted. What is more, investigators only occasionally submitted the trace tape lifts for analysis. Lab officials began to question the value of the trace evidence collection project and whether the benefit was worth the cost. Over time the focus changed to DNA collection, primarily touch DNA. There were several reasons for this. On a couple of occasions, a pathologist’s swab of a bruise or a very light stain on a homicide victim’s skin revealed foreign DNA that helped link a suspect to the crime. These cases alerted the medical examiner staff to the potential power of touch DNA.
