S2: Ep2: Touch Me and Die

It’s never easy, and certainly not common, to exhume a body. In the case of Robert Curley, however, it was imperative to finding out the truth surrounding his death. The trace evidence provided in a single strand of hair told the whole story.
 
Trace evidence is evidence so small that it is hard to see without magnification or enhancements such as alternative light spectrums or chemical treatment. A pioneer in this was Dr. Edmond Locard, who applied scientific methods to the interpretation of trace evidence. Locard’s exchange principle states that “every contact leaves a trace.” Meaning that a criminal will always (unknowingly) bring something on to the crime scene, and leave the crime scene with something.
 
A common item used in trace evidence is hair. Not only is it a valuable factor in the exchange principle, but a single strand of hair contains an incredible amount of information. We pull head hair on every homicide, especially in cases where long-term drug exposure is in question, or when needed for identification purposes. Some basic questions we must ask: Does the hair belong to the perpetrator or the victim? Was the hair cut or pulled? Is the sample good enough for DNA studies?
 
Information contained in hair was so important in this case, that it led to the decision to exhume the corpse. Despite atrophy of the body after years of being buried, we were able to retrieve a hair sample to perform hair segmentation analysis. Hair grows at a standard rate in humans, about 1.25cm a month. Certain drugs and heavy metal will cause lines in a hair follicle at the point of ingestion. It was clear in the case of Mr. Curley that he had ingested thallium salts, which a strand of his hair recorded, line by line. Given the constant rate of hair growth, we could go back from the closest marking on the hair to the scalp and do a retrogression analysis to observe the number and times of the exposure to the poison.

​A strand of hair provided a virtual road map to the victim’s suffering and ultimately his murder. In this way, the body spoke to me from the grave.