Forensic significance of dried seminal and vaginal fluid, biochemical parameters in the corroboration of the occurrence of rape

Background and aims: Rape as a crime is on the increase despite various punitive measures put in place by governments. The major handicaps to the containment of rape are due to societal discriminatory outlooks, poor investigative tools, and expensive empirical evidential biomarkers. Evolving cheap and measurable biochemical biomarkers to bridge these gaps is pertinent. 

Method: Fifty subjects (males and females) were recruited for the study. The subjects voluntarily had unprotected sex with their respective partners. The under wares and pants were collected, seminal and vaginal fluids stained sections were  excised and eluted for biochemical analysis. The subjects were divided into four groups: Group A: Absence of sexual intercourse- Female (ASIF), Group B: Occurrence of sexual intercourse- Female (OSIF), Group C- Occurrence of sexual
intercourse, bathed and washed- Female (OSIBWF), Group D- Occurrence of sexual intercourse, bathed and not washed- Female (OSIBNWF). The above categorizations were replicated for the male counterparts designed as ASIM, OSIM, OSIBWM, and OSIBNWM, respectively. The eluted fluids extracted from both dried seminal and vaginal fluids were estimated for prostate-specific antigen (PSA), acid phosphatase (ACP), gamma-glutamyl transferase (GGT), magnesium, zinc, and phosphorus concentrations.

Results: The result revealed a significant increase (p<0.05) in PSA and ACP both in the seminal and vaginal fluid stained and stained-washed fabrics compared to the unstained. Conclusion: The findings of the study could be applied to the inclusion and exclusion of alleged culprits of rape cases. Furthermore, the use dry seminal and/or vaginal biochemistry could be used as a preliminary test before DNA fingerprinting and profiling.

Keywords: Rape; seminal fluid; vaginal fluid; electrolytes; prostate antigen, acid phosphatase.