A friend of John Allen Muhammad (search) testified Friday that Muhammad introduced teenager Lee Boyd Malvo (search) to him as a sniper and tried unsuccessfully to fashion a silencer for the rifle prosecutors say was used in last year's shooting spree.

"He (Muhammad) said, 'Imagine the damage you could do if you shoot with a silencer," said Robert Holmes of Tacoma, Wash., who had been a friend of Muhammad's since their Army days in the mid-1980s.

Holmes' tip to the FBI that Muhammad might have been responsible for the sniper shootings helped lead to the Oct. 24, 2002, arrests of Muhammad and Malvo after three weeks of sniper attacks in the Washington, D.C., area.

Holmes, testifying for the prosecution in Muhammad's trial, said he observed a father-son type of relationship between Muhammad and Malvo in the spring and summer of 2002.

"He treated Lee just like his own son. I never saw John yell or scream at him," Holmes testified. "He would talk to him and get the result he wanted. Lee didn't really talk a lot."

The director of a Bellingham, Wash., homeless shelter used by Muhammad and Malvo also testified Friday, saying Muhammad "had a very strong influence" on Malvo while the pair stayed at the shelter.

The Rev. Al Archer also said Malvo's mother, Una James, came for Malvo and at one point left with her son for "a secret location" in Bellingham.

Prosecutors had hoped to put James on the stand but she refused to travel to the United States from Jamaica.

"What I observed was that he (Malvo) made an effort to always please Mr. Muhammad," Archer said.

Archer's testimony bolsters prosecutors' arguments that Muhammad, 42, essentially brainwashed Malvo, 18. Prosecutors have said that because Muhammad exerted such influence it does not matter if Malvo was the triggerman in the sniper attacks.

Defense lawyers contend that the triggerman issue is crucial in determining whether Muhammad is eligible for the death penalty.

Malvo has admitted pulling the trigger in most of the shootings, and prosecutors have no known eyewitnesses to testify that Muhammad fired any of the shots.

Muhammad is on trial for one of the 10 killings during the October 2002 sniper spree, that of Dean Harold Meyers (search) at a gasoline station near Manassas. Malvo's trial in another of the killings is set to start Monday. Both could face the death penalty if convicted.

On Friday, the jury was taken to the city jail to see the 1990 Chevrolet Caprice in which Muhammad and Malvo were arrested.

Prosecutors say the former police car, with a specially hinged back seat and notch cut above the rear license plate, was used as a killing platform. They argue that the suspects could crawl into the trunk from inside the car and fire shots without being seen.

Defense lawyers objected to showing the vehicle, saying it is an unnecessary duplication of a demonstration made in court Thursday, and that there is no evidence that Muhammad fired shots from the trunk.

The jurors, who had sent a note to the judge asking to see the car, gathered in a semicircle around it and watched as deputies opened the trunk and lifted the hinged back seat. One of the jurors stuck her hand into the car to see how much space was available to get into the trunk when the seat was dislodged.

Prosecutors on Thursday had wheeled into court the back end of a similar 1990 Caprice to give the jury an idea of how a person might fit into the trunk and use a hole cut from the trunk as a firing platform.

The defense said the demonstrations would invite unfair speculation by the jury.

"There's no purpose except it's real emotional and it makes a big splash," said defense attorney Peter Greenspun.