Chesapeake, Va. -- Lee Malvo was a petty criminal prone to violence long before he met John A. Muhammad and has recently been plotting his escape from custody, two prosecution psychologists testified on Monday at Mr. Malvo's trial here on capital murder charges.
By introducing recent letters from Mr. Malvo to a fellow inmate, prosecutors seemed to suggest that he remained a threat. In the three letters to a fellow inmate at the Fairfax County jail, Mr. Malvo indicated that he was biding his time until he could commit a violent act or escape.
"Get them to think you're somebody you're not," Mr. Malvo advised the other inmate. "My strategy works for me because my enemy does not know me."
"I play the stupid fool," he added. "Everybody underestimates me."
Before, during and after last fall's sniper attacks, the two prosecution experts said, Mr. Malvo voluntarily participated in criminal conduct though he knew it was wrong.
"This is a person who is fully conscious, cognizant, deliberating, purposeful," said Stanton E. Samenow, one of the psychologists who interviewed Mr. Malvo. "Mr. Malvo knew exactly what he was doing."
The portrait of Mr. Malvo concluded the main phase of the trial, which started on Nov. 10. It was part of a single day of rebuttal testimony from the prosecution, and it followed a week of mental health experts for the defense.
The defense experts said Mr. Malvo, 18, was brainwashed by Mr. Muhammad, 42, into participating in the shootings. Mr. Muhammad was convicted of murder last month and sentenced to death.
Closing arguments in Mr. Malvo's trial are likely to be presented on Tuesday. If Mr. Malvo is convicted, the trial will enter a separate sentencing phase.
The prosecution experts described a bright, cunning and ruthless young man. Mr. Samenow, who interviewed Mr. Malvo for 34 hours over eight days last month, quoted a series of statements from Mr. Malvo. They were terse, combative and often studded with profanity.
"I'm willing to question," Mr. Malvo said, according to Mr. Samenow. "I don't take anything at face value. I'm not impressionable. I'm not weak minded."
Mr. Samenow dismissed the notion that Mr. Malvo's actions were in any sense involuntary.
"He made it clear," Mr. Samenow said of Mr. Malvo, "that he was a very, very willful individual."
Mr. Malvo rested his chin on his hand, looking glum, as Mr. Samenow spoke.
Evan S. Nelson, another prosecution psychologist, conceded that Mr. Muhammad was an important influence on Mr. Malvo. But Mr. Nelson said the relationship was better described as idol worship than brainwashing.
"He felt that Mr. Muhammad was a really cool guy," Mr. Nelson said of Mr. Malvo. "It was a consensual relationship that went forward to some very bad ends."
Both experts said Mr. Malvo remained capable of telling right from wrong. The defense must prove the opposite to prevail on its insanity defense.
Mr. Nelson questioned Mr. Malvo's differing accounts of his role in the shootings. Two weeks after his arrest, Mr. Malvo confessed to pulling the trigger in all of the Washington-area shootings. More recently, he has told psychologists for both sides that he mostly acted as a spotter, though he conceded that he shot Conrad Johnson, a bus driver, on Oct. 22, 2002.
Mr. Nelson said defense lawyers might have influenced Mr. Malvo's later account. Their influence, he said, is comparable to what they have accused of Mr. Muhammad of exerting.
"A lot of the same dynamic that people might be concerned about between Muhammad and Malvo in terms of brainwashing," Mr. Nelson said, "may have been recapitulated by the defense."
The defense rested soon after court resumed Monday morning, after presenting the jury with an unusual stipulation about Mr. Malvo and Mr. Muhammad. Craig S. Cooley, a defense lawyer, told the jury that there was no dispute about their heights and weights. As of last October, just after they were arrested, Mr. Malvo was 5 feet 5 inches tall and 125 pounds. Mr. Muhammad was 6 feet 1 inch and 180 pounds.
The defense would have preferred to require Mr. Muhammad to appear in court to demonstrate that he towered over Mr. Malvo, but Judge Jane Marum Roush denied that request two weeks ago, citing security concerns.