OAKLAND -- The Russian mafia, sadomasochism, mental disorders and an allegedly unwanted child were all topics of testimony Wednesday in the trial of Oakland computer engineer Hans Reiser's trial on charges that he murdered his estranged wife Nina.

Reiser's father, 65-year-old Ramon Reiser of Seattle, said he told Hans that the Russian mafia or people associated with sadomasochism might follow him after Nina, who was 31 at the time, disappeared on Sept. 3, 2006.

Hans' attorney, William DuBois, apparently put Ramon Reiser on the witness to try to explain Hans' unusual behavior after Nina was last seen alive when she dropped off the couple's two children off at him home at 6979 Exeter Drive in the Oakland hills. The couple had been separated for two years and was in the midst of bitter divorce and custody proceedings.

Several Oakland police officers testified earlier in Hans Reiser's lengthy trial that he engaged in classic countersurveillance techniques, such as hiding his car and driving at irregular speeds and taking unusual routes, when officers followed him in the weeks after Nina disappeared.

Ramon Reiser, a former Army veteran and mathematician, said he warned his son that he might be surveilled by people associated with the former KGB, "Russian mafia groups in California" or "the techno-geek S&M crowd."

The body of Nina Reiser, who was born in Russia and was trained as a physician there before coming to the U.S. in 1999 to marry Hans Reiser, has never been found, despite extensive searches in the Oakland hills and elsewhere. But Hans Reiser, 44, was charged with murdering her because prosecutors believe that DNA and blood evidence proves that he killed her.

He has pleaded not guilty to the charges against him.

DuBois has said that Nina Reiser may still be alive and be in hiding in Russia, where she was raised and was trained as a doctor.

DuBois also has suggested that Nina may have been killed by Russian spies, alleging that her family has connections with Russian spy organizations.

In addition, DuBois has suggested that Sean Sturgeon of Oakland, who was one of Hans' best friends at one point and had a lengthy affair with Nina, was into S&M.

Ramon Reiser testified that Hans and Nina were in Russia in 2001 because Hans' computer file system company had extensive business there and they asked him to join them "to protect her (Nina) from the mafia."

But Alameda County Superior Court Judge Larry Goodman struck that remark from the record and told jurors to disregard it, apparently because he doesn't think there was a legitimate basis for it.

Goodman also frequently admonished Ramon Reiser not to give rambling answers and struck many comments by him from the record because they didn't directly respond to questions he was asked.

Ramon Reiser suggested that Nina was phony, saying that she was "smiling with adoring eyes" at Hans in public but privately told him that she was unhappy with her marriage to Hans.

Reiser also said Nina was a bad mother to the couple's young boy and girl, alternately playing with them and then ignoring them and letting a nanny take care of them.

Reiser said, "She would turn off totally" and claimed it was "bizarre and scary" when she wouldn't respond to her children.

In addition, Reiser said that in November of 2001 Nina told him that she had promised the couple's first child, their son Rory, that she wouldn't have another child, but "Hans made me break my promise" and she wound up having a second child, their daughter Nio.

Ramon Reiser said, Nina told him, "I'll never forgive him (Hans) and said to Rory "We would just accept her (Nio) but she will never come between us. She will never be more than accepted. She will never be fully part of us."

Reiser said he thought Nina's comments were "bizarre" as well as "sick and disturbing."

But when prosecutor Paul Hora cross-examined Reiser, he expressed skepticism that the conversation occurred as Reiser recounted it, noting that Rory was only two years old at the time.

Late in the day, Southern California psychiatrist Beverly Parr, who's been a friend of Hans Reiser's mother, Beverly Palmer, for many years and has known Hans since the age of two or three, testified that she thinks that Hans might suffer from Asperger's Disorder, which she said is a milder variant of Autistic Disorder and is characterized by "impairment in social interaction" and poor communication skills.

But under cross-examination by Hora, Parr admitted that she's never diagnosed Hans Reiser because "he hasn't been a patient of mine since I don't treat my friends and their family members."

Hora suggested that Reiser's personality quirks, such as being obsessed with himself, indicate that he suffers from "narcissistic personality disorder" instead of from Asperger's Disorder, but Parr disagreed, saying, "I haven't witnessed those symptoms in Hans."

Parr will complete her testimony Thursday morning, when Reiser's trial resumes. Palmer, who waited in the hallway outside court today, is expected to follow her on the witness stand.

Ramon Reiser testified that he and Palmer separated in 1968, when Hans was only five years old, and their divorce was finalized either late that year or early in 1969. He said Hans mainly was raised by Palmer.