OAKLAND, Calif. -- A software programmer charged with killing his estranged wife, sparred with a prosecutor as cross-examination in his murder trial began Tuesday, saying the idea that he hasn't been forthcoming with information is "ridiculous."

The tone of the exchange was set early as Hans Reiser objected to a question from prosecutor Paul Hora regarding whether Reiser had been obliged to provide police with his car, for which they had obtained a search warrant after Nina Reiser disappeared.

"You're kind of asking me for a legal conclusion, sir," Reiser said, going on to say, "I don't have a great deal of desire to give the government all my possessions. Not my underwear (a reference to an earlier police search), not my car and definitely not my children."

"And not information about where Nina was either, right?" Hora said.

"Your question's ridiculous," Reiser replied.

Hora, who began cross-examination Tuesday after Reiser finished more than four days of direct testimony, confronted him with a series of questions about what happened Sept. 3, 2006, the afternoon Nina Reiser disappeared after dropping the couple's two children off at Hans Reiser's home.

Reiser, known in programming circles for his ReiserFS computer file system, has testified that he knows nothing about her disappearance. He says after she arrived with the children, the couple talked for about an hour about the children and their divorce and the last time he saw Nina Reiser she was driving away from his house.

Her body has never been found and the defense has suggested she may be living in her native Russia. But prosecutors say Nina Reiser would never have left her children. They say DNA and other evidence point to Reiser.

Hora asked Reiser if the conversation on Sept. 3 had turned into a sudden quarrel.

"Did you strike her?" Hora asked.

"No, I did not," Reiser replied.

"Did you apply any physical force to her?"

"No, I did not," Reiser said.

"Did she provoke you in any manner whatsoever that afternoon?" the prosecutor asked.

"No. We did, however, have a contentious divorce that we did discuss," Reiser said.

"So you certainly didn't kill Nina in the heat of passion?" Hora said, going on to enumerate a number of other scenarios, including manslaughter, involuntary manslaughter and accidental injury.

Reiser said none of those things happened.

"I certainly didn't kill Nina," he said.