Аннотация
Identifying semen stains on clothing and bedding is a crucial component in investigating cases of sexual assault. In some cases, clothing and bedding have already been washed before they were removed and sent for forensic examination. There is insufficient data on best practices for handling traces of semen on clothes after washing. This work aimed to study the possibility of identifying traces of semen on clothes after washing using widely used techniques. To simulate typical physical evidence, donor semen samples were applied to pieces of clothing made from various fabrics. The clothes were washed under multiple conditions (with the help of nonbiological and biological (enzyme-containing) agents, and across numerous washing machines). After washing, the washing stains were characterized by the presence of fluorescence signal, spermatozoa (Koren – Stokis method), the determination of acid phosphatase, prostate-specific antigen and semenogelin, as well as the results of serological research according to the AB0 system and DNA analysis. Clothing analysis using these methods was shown to be effective in experimental conditions. However, the presence of enzymes as detergent components designed to destroy biogenic stains significantly affect the results of the identification of semen stains. It has been established that the full genetic profile can be obtained from semen stains even after washing three times. Different strategies are needed to detect, select and identify semen stains depending on the circumstances of a case. It is recommended to examine clothing and bedding, even if the specimens were previously washed.