Trace Evidence vs Memory Evidence: Comparing Evidence Collection Tools

Memory evidence and forensic evidence are both residual traces of an event. While traditional trace evidence (hair, fiber, blood, fingerprints, etc.) is left behind by a perpetrator, memory evidence resides in a person’s mind, usually that of a victim or witness. Both types of evidence have the possibility of contamination; given that memory evidence cannot be bagged and tagged like other types of forensic evidence, it is especially susceptible to contamination which can undercut its ultimate reliability. In court, jurors often have trouble conceptualizing the complexity of memory or even thinking about it as evidence at all. Drawing similarities between memory evidence and trace evidence provides a framework for jurors to make sense of evidence collection procedures as they relate to memory, including the concepts of training of the collectors, policies, procedures, protocols, tools, and analysis. By comparing forensic and memory collection tools, we can begin to understand memory evidence as a form of trace evidence.