Scent evidence is valuable because it can establish probable cause for arrest or provide positive identification in some cases. Human scent, like fingerprints, is unique to each individual and cannot be masked. Scent discriminating dogs can detect sweat, oils, gases, and shed skin cells. Scent discriminating dogs are beneficial to law enforcement in many ways. In addition, scent can be collected by placing a sterile gauze pad on the evidence and trapping the scent in the gauze. This is accomplished with the Scent Transfer Unit, STU-100. However, when it involves proving a person’s innocence or guilt in court these methods have been controversial and require corroborative evidence. The future holds hope in proving beyond a shadow of a doubt to the scientific community that scent is evidence, that it’s always there and trackable, and that it has the ability to be used to solve crimes.