A criminalist testified Wednesday morning that DNA found on pantyhose worn by a murder victim whose body was found in Marin County in 1977 contained semen that is likely that of Joseph Naso.

Contra Costa County sheriff's Deputy Tuan Nguyen, a criminalist who processed and examined the DNA, also said DNA taken from another pair of pantyhose found around victim Roxene Roggasch's neck matched that of Naso's former wife, Judith Naso. Roggasch, 18, was found dead on the eastern slope of White's Hill near Fairfax on Jan. 11, 1977.

Naso, 78, of Reno, was charged with killing her and three other women -- one other woman from the Bay Area and two from Yuba County -- between 1977 and 1994. All four women are believed to have been prostitutes.

At Naso's preliminary hearing in Marin County Superior Court Wednesday morning, Nguyen testified that he processed DNA taken from sperm found on the inside of the pantyhose Roggasch was wearing when her body was found.

He said the sperm was from two males, and that one of the samples "likely" came from Naso.

When Naso cross-examined Nguyen, he asked, "How can that be? I don't understand."

"Do your tests lead one to conclude I had sex with this woman?" Naso asked.

"That's one way sperm can be deposited, but also through drainage after intercourse," Nguyen responded. "To say sex definitely happened, I can't say."

Nguyen said, "You are likely the source as Male B. We can never say you are, just likely are."

Nguyen also testified that a third pair of pantyhose was found in Roggasch's mouth and a fourth pair was wrapped around her mouth.

On the fourth pair, there was "contact" DNA from at least four individuals, Nguyen said. It was of poor quality and he was unable to develop individual DNA profiles on it.

He said he did not develop a DNA profile for the pantyhose inside Roggasch's mouth because it would contain too much of Roggasch's own DNA.

There was also a white cloth belt wrapped around Roggasch's knees, Nguyen said. The belt contained degraded DNA from at least two people, but Nguyen could not develop a profile, he said.

Johanna Estrada-Ballardo, another criminalist with the Contra Costa County Sheriff's Office, testified that DNA was extracted from a fingernail clipping from murder victim Carmen Colon, 22, whose body was found near Port Costa in Contra Costa County, in 1978.

Most of the DNA was Colon's, but there were trace levels of DNA from a male and one other person of unknown gender, Estrada-Ballardo said.

That DNA was compared to Naso's DNA, but Estrada-Ballardo said she was unable to match the samples taken from the fingernail clipping to any individuals.