DNA on the inside door handles of entrance doors

Abstract

DNA from door handles on entry doors could provide a clue as to who last left the scene. However, after years of extensive research on DNA transfer and persistence it can be considered common knowledge that general claims like "the last who touched leaves the most DNA" do not hold true. But who's DNA do we find on door handles that are usually used several times per day by the inhabitants? To assess this question, we sampled inside door handles from real-life burglaries and at the same time collected reference samples from all the inhabitants, to determine if we can detect any (major) profiles from non-inhabitants. We also searched to evaluate how often we detect DNA from the person who last touched the door handle as a (major) contributor. Only small amounts of DNA were recovered from the handles, originating most often, but not always, from inhabitants or even the last inhabitant touching the handle.