In the late 1980s, an idea for preserving scent came from the musings of William D. Tolhurst of Lockport, New York. Bill was a scent dog training expert as well as a pioneer in the field of scent. When he envisioned a way to collect scent from anywhere and make it a portable tool for scent dog teams, he began building his prototype. It was quite large and required more than one person to move it to the scene.
Despite being a large and cumbersome machine, Bill found that his mantrailing dogs were still successful in finding suspects using the collected portable scent material.
Once Bill began collaborating with Larry Harris, an engineer and law enforcement Bloodhound handler from California, they successfully shrunk the size of Bill’s scent collection unit and the portable, easy to use STU-100 was born.
Bill always advised dog handlers to do their own testing whenever they were presented with a situation involving scent and/or dog work. As a result of his own constant testing, Bill determined that scent could be gathered from any object and any location (a door knob touched by a suspect, a footprint found at the scene, a melted gas can left behind at the scene of an arson, around/inside a shallow grave, etc.) and be used successfully to mantrail a suspect.
STU-100s have been operational since 1996 and are the only scent collection machines that have been scientifically proven and court-tested. The STU-100 is also the only scent collection machine used by the FBI.
In the judicial world, a Kelly Hearing determines the reliability of a piece of scientific equipment. In March of 2005, the STU-100 passed a Kelly Hearing in Los Angeles Superior Court in the case of People v. Benigno Salcido.
Bill Tolhurst's original website does have good information about scent and the use of scent. Bill was quite innovative and he and his teachings are sorely missed by those of us who knew and worked with him.
Bill’s original STU website: www.angelfire.com/ny4/bigT/