Y‐Chromosome DNA identification of aspermic male offender from vaginal swab of victim

Abstract

Identification of the offender from spermatozoa andblood is the most often sought biological evidence inthe examination of rape victims. Forensic finding of thespermatozoa plays an important role to confirm therecent episode of sexual intercourse. Problems arise incases of digital penetration and vasectomized males.Criminals are getting smarter now days, they are usingcondom to commit rapes or ejaculate away from thebody of victim. In such cases no sperm cells are foundand conventional STR testing yields only a femaleprofile. This study demonstrates the presence of themale epithelial cells in the vaginal tract as availableproof of coitus. In many circumstances the applicationof PCR?based DNA typing methods results in the failure to amplify the minor (e.g., male) component of DNAmixtures due to competition with alleles from the major(e.g., female) component. In this study DNA profile fromthe aspermic semen, vaginal swab and a control sampleof a vasectomized male was obtained for all 16 Y?STRloci namely DYS392, DYS390, DYS385 a/b, DYS393,DYS3891, DYS38911, DYS391, DYS19, DYS439, DYS438,residing on the Y?chromosome and Amelogenin to helpthe investigating agencies to prove that a male wasinvolved in the offence and further investigation wasneeded.