Abstract:
Determining the order of events in a criminal investigation can be crucial in many ways. Although the use of fingermarks is one of the most important forensic tools as a modality of individualisation, placing them in time is a long lasting difficulty. In the study presented in this paper we describe the effects of light and the temperature on depositions of standard solutions containing squalene and cholesterol on paper. The results obtained give a clear view on what type of processes take place during a temperature and a light influenced degradation of the two materials in this study. Using well known methods for the determination of reaction constants it was determined that the degradation mechanism of cholesterol is following a radical route, where the decay of squalene is more affected by temperature.