Scientific testimony took center stage Wednesday during the third day of trial for a man accused of being a serial rapist.

The 39-year-old Sacramento, Calif., man is facing multiple rape and sodomy charges in Douglas County District Court, stemming from sexual assaults on two women in Lawrence in the mid-1990s.

Sindey Schueler, a DNA examiner at the Kansas Bureau of Investigation at the time of the crimes, testified Wednesday during the trial. She said investigators originally weren’t able to come up with a genetic profile for a suspect. But newer, more sensitive tests revealed the defendant’s DNA on evidence from the crime scenes.

On cross-examination, defense attorney Jim Rumsey tried to point out how easy it would be for the lab to make a mistake while testing multiple samples from different cases.

“I keep each case separate,” Schueler testified. “To cross-contaminate from one case to another case, there would have to be physical contact.”

The trial, which started Monday, is expected to last the remainder of the week.

The Journal-World typically does not identify suspects in sex crimes unless there is a conviction.