The DNA in Underwear

Attorney Sontz tried this case with a colleague. Attorney Sontz handled the DNA portion of the case.

The client recently immigrated to the United States. He rented a room in a house with a number of other recent immigrants from the same country. He shared the room with a young woman. Their living space was divided by a curtain.

One night the woman claimed that the defendant had snuck into her section of the room while she was sleeping and raped her. The defendant adamantly denied the accusation. She called the police.

The police investigated and seized evidence from the scene. The accuser’s clothing was collected and submitted to the State Police Laboratory in Greensburg for analysis. The DNA evidence was also submitted to a second forensic laboratory for further statistical analysis called probabilistic genotyping. This is complicated and technical form of analysis that relies on computer software to create statistical models of the DNA evidence to determine the likelihood that that the DNA came from the defendant rather than some other random person.

Through the DNA analysis, the police discovered Y-STR DNA that appeared to match the defendant in the crotch section of the accuser’s underwear. They also found a sperm cell. In other words, on first examination, it appeared that the DNA evidence supported the charges.

At trial, both the Commonwealth and the defense called expert witnesses on the science of DNA. Through meticulous preparation, the defense was able to show the jury that the DNA evidence was actually inconsistent with the accuser’s claim about what happened.

The vast majority of criminal defense attorneys would have counseled the defendant to either take a plea or defend the case on a theory of consensual sex. However, the defendant was adamant that he never had sex with the accuser. So, the defense took the case to trial notwithstanding the misleading DNA evidence.

After a few hours of deliberation, the jury returned a verdict of NOT GUILTY on all counts.