Two related NIJ-supported studies evaluated the possibility of using an individual’s skin microbiome — a community of microorganisms that inhabit a specific environment — as a form of trace evidence from evidence found at a crime scene. The first study, led by Dr. Rob Knight of the University of California, San Diego, examined whether the sequence in which surfaces are touched by an individual, along with the number of times the surfaces are touched, influences the detection of the person’s microbiome.