CHESAPEAKE, Va. (AP) — A theory advanced by the prosecution against sniper suspect John Allen Muhammad is being embraced by attorneys for Lee Boyd Malvo in their efforts to keep the younger suspect off Virginia's death row.

Malvo's trial was to begin Monday in Chesapeake, and defense lawyers plan to argue the 18-year-old is innocent by reason of insanity.

Prosecutors in nearby Virginia Beach are trying to convince a jury that Muhammad, 42, exerted such control over Malvo that Muhammad should be held responsible for the shootings that killed 10 and wounded three in the Washington area last fall.

"Our strategy is their strategy," Malvo lawyer Michael Arif said. "If you watch the prosecutors (in Muhammad's case) carefully, they will never put on evidence that Lee was the shooter in any of the shootings in question."

The defendants are being tried for different killings by prosecutors from two Virginia counties. Both face the possibility of the death penalty if convicted.

Prosecutors from Fairfax County say Malvo, who is charged with murder in the Oct. 14, 2002, death of FBI Analyst Linda Franklin, has admitted committing many of the shootings.

His lawyers argue that he confessed only to protect Muhammad, whom he called father, and that Muhammad was the mastermind of the sniper attacks.

Even if that is true, the prosecutors argue, Malvo is equally responsible for the killings. They say he laughed and bragged about the shootings to interrogators and prison guards.

During the first three weeks of Muhammad's trial, prosecutors from Prince William County combined emotional testimony from victims and victims' relatives with forensic evidence, including DNA linking Muhammad to a rifle sight found in his car. Like Malvo, Muhammad is on trial only for one killing, but to get the death penalty, the prosecution needs to prove participation in multiple killings or terrorizing of the public.

For Malvo's attorneys to succeed with an insanity defense, they must convince a jury that he was so brainwashed by Muhammad that he either did not know what he was doing or could not control himself.

It likely will be a tough sell -- and risky.

Studies have indicated that defendants who mount insanity defenses generally have higher conviction rates than those who don't, said Thomas L. Hafemeister, director of legal studies at the Institute for Law, Psychiatry and Public Policy in Charlottesville.

"A lot of people see insane individuals as both very bad and very scary," said Hafemeister, who also teaches at the University of Virginia law school. "The risk for the defense is that if they fail to convince the jury, then essentially they have a defendant who has acknowledged doing the deed and being mentally unstable, which creates a very scary person in the minds of the jurors."

Insanity defenses are raised in about 1 percent of felony cases in the United States, and heard by juries in even fewer, Hafemeister said.

In the string of sniper attacks last fall, it remains unclear who actually pulled the trigger in each of the shootings.

Investigators have testified that Malvo's fingerprints were on the .223-caliber rifle used in the sniper killings, and that his DNA or fingerprints were found on evidence from several of the scenes.

Muhammad's prosecutors argue it doesn't matter who pulled the trigger and say Muhammad, who referred to Malvo as his son and plunged him into a lifestyle of rigor and discipline, was the "moving spirit." That most of the evidence can be traced to Malvo only shows how carefully Muhammad controlled the situation, they contend.

Malvo's mother, who was deported to Jamaica in 2002, says she is convinced Muhammad manipulated her son. They had met Muhammad in the Caribbean, and after she and Malvo immigrated to the United States, Malvo and Muhammad were reunited in Bellingham, Wash., where the teenager lived with Muhammad in a homeless shelter as father and son.

"It doesn't excuse what had happened, but it all went back to the serious influence this man had over this child," Una James said in an interview from Jamaica aired Monday on ABC's "Good Morning America."

"Yes, he's a part of it. He will have to take whatever blame," she said. "But look at it. Muhammad has manipulated this child to death."

Malvo's jury trial was moved to Chesapeake, 200 miles south of Fairfax, because of extensive news coverage and the climate of fear the shootings had created in the Washington area. Muhammad's trial was moved to Virginia Beach for the same reasons.