SCENT IDENTIFICATION IN CRIMINAL INVESTIGATIONS AND PROSECUTIONS: NEW PROTOCOL DESIGNS IMPROVE FORENSIC RELIABILITY

John Ensminger, Delta Hedge Consulting

Abstract

Scent lineups are a powerful tool in the investigation of crimes. With proper procedures, both forensic and judicial, scent lineups can be valuable evidence for a jury to consider. Unfortunately, many courts have been willing to admit poorly conducted procedures, even if giving lip service to the fact that the scent lineup was deficient by saying that its admission was harmless error. The tendency of some courts to view scent lineups as an extension of scent tracking has resulted in admission of scent lineup evidence under inappropriate standards. Tracking cases have set foundational requirements from long-held social and judicial assumptions about the accuracy of dogs. Although no specific set of training procedures or testing protocols need be imposed for the conduct of scent lineups, protocols with elements that have produced highly reliable results should be developed by law enforcement authorities and insisted upon by courts. The authors believe that scent lineups under such protocols can now satisfy the Daubert standard for admissibility of scientific evidence, though perhaps not the Frye standard (because of the lack of general acceptance in the scientific community). Because the possibility of a false identification cannot be completely eliminated, corroboration by other evidence should be required, probably at a clear and convincing level.