Pre-ejaculatory fluid - identification of hitherto disregarded evidence in sexual assault cases

• Applicant: Dr. Hannah Bauer
• Subject Area: Toxicology, Laboratory Medicine
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 533747730

The identification of forensically relevant bodily fluids serves, among other things, as highly important evidence in the investigation of sexual offence cases. The detection of semen is of particular importance in connection with sexual offences; it unambiguously helps to prove that a sexual act has taken place. Conversely, however, this does not mean that without sperm, i.e. without ejaculation, no (possibly criminally relevant) sexual act has taken place. The processing of sexual offence cases shows that pre-ejaculatory fluid, commonly referred to as "pre-cum", could be an underestimated body fluid in forensics, especially, if no ejaculation is described. Pre-ejaculatory fluid is generally free of sperm, but has a high DNA content and can be used for generating STR profiles suited for comparison with a suspect or databank. It is secreted during sexual arousal and indicates a sexual act even without ejaculation. Currently, there is no method that allows for the identification of this body fluid and its distinction from semen. This project aims to characterize the proteome and metabolome of pre-ejaculate and semen. With the help of this data, specific antibodies will be generated, which serve as a confirmatory test for pre-ejaculatory fluid. A positive proof of pre-ejaculate at a crime scene and its differentiation from semen highly elevates the value of evidence in sexual assault cases.

• DFG Programme: Research Grants
• Co-Investigators: Dr. Jennifer Schürenkamp; Privatdozentin Dr. Marielle Vennemann