Forensic samples, such as those from sexual assault cases, which contain male sperm cells mixed with male and female epithelial cells always pose challenges for DNA scientists in Forensic laboratories. Sometimes, it becomes more challenging when there is a mixture of male epithelial and sperm cell of petrilineal suspect. It is very difficult
to obtain DNA profile from a mixture of two different sources with different quantity. In the present paper, we report a case of sodomy and murder, in which culprit was a petrilineal relative to the deceased. To identify the culprit through DNA technology only autosomal STR markers were helpful and Y STR markers were not helpful in this case, due to the culprit was petrilineal relative of the deceased, having same DNA Profile of Y lineage STR markers . DNA profile obtained from semen stains detected on kameej of deceased, chaddi of suspect, anal swab of deceased, soil and hair recovered from crime scene exposed the suspect to be involved in the crime.

Keywords: Sodomy; Homicide; Forensic; DNA; STR.