DNA transfer in an office space visited by an intruder after resumed use by the owner

Abstract

Knowledge of DNA-TPPR in various settings and circumstances can aid sample targeting and collection, interpretation of DNA profiles, and activity level assessments. The present study looks at a number of items/surfaces in a single-use office space that was sequentially used for one hour by the owner, a temporary occupant (intruder), and the owner (3 h total). Video recording allowed evaluation of contacts made by participants to assist targeted sampling. In a majority of samples, the owner of the office space was the major contributor regardless of the last person to have contacted an item/surface. The DNA of the intruder persisted after contact on 7 of 19 items/surfaces that the owner of the office space re-used. Interestingly, the participants picked up DNA from each other on hands and clothing via indirect transfer.