VIRGINIA BEACH, Va. - As the trial for his life got under way yesterday, John Allen Muhammad shocked the court by firing his lawyers and delivering an elliptical opening statement in which he claimed direct knowledge of the sniper shootings only to, moments later, deny any involvement.

"We know something happened," Muhammad told the jury after the prosecution's opening statement methodically linked him to 16 shootings over two months last fall. He then belittled the prosecution case as an unproven theory, saying emphatically, "They wasn't there. I was. I know what happened."

Later in his 22-minute statement, Muhammad appeared to contradict himself when he said, "The evidence will show that I had nothing to do with these crimes, directly or indirectly. ... What we're looking for here is not complicated. We need to have answers. We need to know what was done."

At that, he briefly broke down. His voice cracked and he appeared to heave and sob before regaining composure.

Judge LeRoy F. Millette Jr. questioned Muhammad, 42, at length about his sudden request to represent himself and reluctantly allowed him to do so. The judge designated Muhammad's attorneys to stay on as standby counsel to occasionally advise Muhammad, who has not completed any formal education beyond high school.

"Let the record reflect that the court has granted a motion by Mr. Muhammad that he represent himself," Millette said after conferring with lawyers and the defendant at the bench. "After lengthy interrogation of all parties, the court has granted the motion."

Muhammad is on trial in the killing of Dean H. Meyers, a 53-year-old Vietnam veteran who was gunned down outside a Northern Virginia gas station last October. In a rambling and philosophical opening statement, Muhammad gave little clue as to why he fired his lawyers, two veteran defense attorneys considered among the best in Virginia and who have been working on his case for a year.

But Muhammad did say he was tired of the negative things being said about him in the media and he wanted to present an alternate view.

Perhaps aware of a widely held assumption that his lawyers would essentially concede their client's guilt and instead focus on saving his life, Muhammad said he did not want the jury to see their choice as "dirty glass No. 1 or dirty glass No. 2."

"My response is to set a clean glass of me alongside these dirty glasses," Muhammad told the jury. "The only reason you've been drinking out of a dirty glass is because you had a choice between dirty glass No. 1 and dirty glass No. 2."

Speaking from notes scribbled on a yellow legal pad, Muhammad discussed the nature of truth and said it comes in three kinds - "truth, the whole truth and nothing but the truth." He said Jesus taught "Ye should know the truth" but these other forms of truth have emerged as people have grown deceitful and evil.

"Listen to [the evidence] carefully," he told the jury. "It will show I had nothing at all to do with these crimes. They know that. Pay attention. Please pay attention because right now my life and my son's life is on the line."

Muhammad repeatedly referred to 18-year-old Lee Boyd Malvo, his alleged co-conspirator, as his son. The two did not meet, however, until Malvo was 15 years old and living on the Caribbean island of Antigua with his mother.

Prosecutors said they did not know of Muhammad's decision to represent himself until this morning. They said it will be challenging and frustrating to argue against someone who has no legal training, but they will not soften their approach.

"This will be a hard-fought battle," said prosecutor James A. Willett in his 90-minute opening statement. "We will make him play by the rules. We represent hundreds of thousands of people, so we are not going to lay down just because he's representing himself."

Muhammad's own lawyers looked defeated and ashen after they had been removed as counsel. At one break yesterday, defense lawyer Jonathan Shapiro stood with his back against a wall in the courtroom, his eyes downcast and his hands in his pockets. Asked to comment later, he said only, "Nothing."

One of Malvo's defense lawyers, however, said Muhammad's decision amounted to a death wish.

"It's absolute foolishness, absolute foolishness," said Michael S. Arif. "These are big stakes, man. This is not traffic court."

The day got even stranger in the afternoon when Malvo appeared in court to be identified by a witness. It was the second courtroom meeting for the two suspects in less than a month, after they had not seen each other all year.