Timing forensic samples can be seen from two different aspects: i) how many days, months, years ago a sample was placed at a crime scene (sample age), and ii) the time of the night and day a sample was placed at the scene. Both aspects can be highly relevant for crime scene investigating as they can potentially provide support for linking sample donors identified via DNA profiling with criminal acts. However, current approaches for trace timing are highly limited. To address the age of a sample we are investigating differential degradation behaviour of various biomarkers. For estimating day/night sample deposition time we are exploring circadian biomarkers thereby bringing a chronobiological aspect into forensic sciences. We also test the suitability of the bio-markers generated for trace timing, in time of death and time since death estimations.

Selected recent publications:

• Ackermann K, Ballantyne KN, Kayser M (2010) Estimating trace deposition time with circadian biomarkers: a prospective and versatile tool for crime scene reconstruction. International Journal of Legal Medicine, 124(5):387-395.