Trace Evidence

In 1990 in Telluride, Colorado, Eva Shoen's young daughter found her dead from a single gunshot to her head.  Her husband, Sam, came under suspicion, but he truly appeared to be the grieving, shocked husband, a victim of random violence.  The police were confident they would solve the case, because the bullet taken from Eva's skull had the distinct markings of a particular type of pistol.  However, the case eventually found its way into the cold cases file.  There just were no leads.

Three years later, the Telluride police received a call from a man in Arizona who believed that his own brother, Frank Marquis, had been the perpetrator.  Marquis had once confessed this crime, but an attempt to trap him during a phone conversation failed.  Nevertheless, when the gun was recovered, an arrest seemed a sure thing.  Unfortunately, Marquis had covered his tracks all too wellincluding tampering with the barrel of the gun so that the bullet fired from it could not be matched.  All they had on him was a hearsay conversation.

However, tracing Marquis's movements indicated that he had indeed been in Telluride during that weekend for a festival, and that he had a police record for rape.  This was the man, the detectives felt, and they had to find a way to get him.  Putting pressure on Marquis' travel companion, they learned that at some point along the road back, Marquis had tossed two bundles out the window of the car.  They suspected that this was the clothing he had worn to commit the crime.  Still, it was a long and winding road between Telluride and the point where Marquis had ended his journey some four hundred miles away.

Detectives scoured the roadway until they narrowed the possibilities down to four places.  As luck had it, a construction crew had recently moved a pile of dirt, exposing a bundle of clothing that the dirt had preserved.  On the shirt was a single strand of hair, which was examined in the lab against a sample taken from Eva Shoen.  Forensic trace expert Joseph Snyder analyzed the color and structure, and pronounced them a close match. 

When the investigators told Marquis of their findings, he confessed.  It was a bungled burglary, he said, indicating his knowledge of the plea-bargaining system.  Although the officers in charge of the case believed that he had in fact planned to rape Eva Shoen and had killed her in the process, they knew that this would be impossible to prove.  Marquis got a sentence of twenty-four years for manslaughter. 

Sometimes a single strand of hair will make all the difference between a case closing down and a lead that opens it in an entirely new direction.

Is the analysis really that sophisticated or does it just bolster a good guess?  To answer that question, we need to examine the technology.