CHESAPEAKE, Va. - Lee Boyd Malvo's lawyers waged an elaborate insanity defense. They called four mental health experts who said their client didn't know right from wrong. They brought forth witnesses to talk about Malvo's abusive childhood. They showed drawings Malvo made that exalted Saddam Hussein and Osama bin Laden.

The defense attorneys pulled out all the stops. And they still lost.

A jury's decision yesterday to reject Malvo's insanity defense and convict him of capital murder was exactly what prosecutors wanted in the pursuit of the death penalty for the teen-age sniper. The verdict also illustrates the reluctance of juries to buy into an insanity defense when the crime is so violent.

"If a person is mentally ill, yet capable of extreme acts of violence, they are just as frightening to the average juror" as a sane person, said Steven D. Benjamin, a Richmond criminal defense lawyer. "Jurors may find, despite the law, that a person's inability to resist violent impulses is exactly why they should be convicted."

Insanity defenses are used in less than one-half of 1 percent of criminal cases, and they are successful less than half of the time they're used. It's even more difficult to win an insanity defense in Virginia, where the legal standard is set higher than any other state, according to defense attorneys here.

Lawyers in Virginia must prove that the mental disease was the direct cause of the crime, not merely a contributing factor. In Malvo's case, the defense team argued that Malvo's intense indoctrination by John Allen Muhammad made it impossible for him to know right from wrong.

His defense entailed finding mental health experts to spend hours meeting with Malvo, subjecting him to evaluations from prosecution experts, and tracking down more than a dozen of Malvo's friends and relatives in his native Jamaica to testify to his troubled, abusive childhood.

'Brilliant job'

"I think that Malvo's attorneys have done a brilliant job for their client," said Peter D. Greenspun, the lead attorney for Muhammad, who was convicted of capital murder last month. "It was an incredible effort, and from a personal point of view, I think it will assist them in avoiding the death penalty."

As they laid out an exhaustive insanity defense over the past weeks, Malvo's lawyers also were meticulously building what typically is the centerpiece of a death penalty defense: evidence of their client's troubled mental state.

Underlying tactic

Michael A. Millemann, a University of Maryland law professor who has worked on capital cases, said that might have been the defense lawyers' underlying strategy from the start, given that the standard for jurors to consider mitigating evidence at sentencing is far more lenient than in the guilt phase of the trial.

"I don't think the defense really ever thought they were going to persuade a jury that he was insane and he was going to be acquitted," Millemann said last night.

Jurors could conclude that Malvo's troubled childhood and the powerful influence of Muhammad argue against sending the younger of the two defendants to Virginia's death row, Millemann said, even if they were unconvinced that Malvo did not understand right from wrong.

"That's a very strict test," Millemann said. "It's hard for anybody to really show they didn't know right from wrong."

Paul B. Ebert, who was the lead prosecutor in the Muhammad trial and who might get a chance to try the teen-ager in Prince William County, Va., said he never bought the youth's insanity defense.

"I think this was an attempt on Malvo's part to hoodwink a jury, and I'm thankful that they didn't buy that," Ebert said. "It was clear to me this was a killing team, and Malvo was just as active a participant as Muhammad."

Harmed by own words

The insanity defense was dealt serious blows by letters Malvo wrote in recent months that asserted he was "playing the fool" - letters that suggested Malvo knew exactly what he was doing all along. Furthermore, Malvo's taped confessions to police shortly after his arrest were hard to overcome, legal experts said.