Abstract

Biological evidence plays a crucial role in establishing a connection between the victim and the suspect in cases of sexual assault. However, the use of condoms during such offenses significantly reduces the likelihood of obtaining DNA from biological samples. In these instances, the detection of chemical residues, such as lubricants, obtained through genitorectal examinations of the victim, can serve as evidence of condom use and support the assertion that the offense was committed with a condom. Particularly in cases where DNA evidence is unavailable, identifying the presence of lubricants or their substitutes within condom residues or as directly applied substances can help establish a link between the victim and the suspect. This study aimed to create a comprehensive lubricant database by analyzing various condom brands, lubricant gels, and alternative substances that can function as lubricants using Attenuated Total Reflectance - Fourier Transform Infrared Spectroscopy (ATR-FTIR) spectroscopy. The results demonstrated that Infrared (IR) spectra effectively differentiate condom brands and types, as well as lubricant gels and comparable substances, enabling the identification of their chemical compositions. Consequently, a database was developed for the forensic identification of condoms and lubricants recovered from crime scenes, to enhance the forensic investigation and elucidation of sexual assault cases.

Key words: Forensic science, sexual assault, physical evidence, condoms, lubricants, database