As the prosecution moves toward the expected testimony of Lee Boyd Malvo as early as Monday, a ballistics expert testified yesterday that all but two of the people hit by sniper's bullets during the 2002 Washington-area shootings could only have been shot by the .223-caliber Bushmaster rifle found in John Allen Muhammad's car at the time of his arrest.

Bullets taken from the bodies of eight people who died and three who were wounded were fired from the Bushmaster, ballistics expert Walter Dandridge of the Bureau of Alcohol, Tobacco, Firearms and Explosives told the jury.

The rifle was hidden in Muhammad's 1990 blue Chevrolet Caprice when he and Malvo were arrested at a rest stop on Oct. 24, 2002.

Malvo, now 21, is expected to testify against his former mentor as early as Monday and tell jurors that he pulled the trigger only in the last of the six killings in Montgomery County for which Muhammad is on trial, a source familiar with the case said. That is the fatal shooting of bus driver Conrad E. Johnson, felled early on the morning of Oct. 22, 2002, as he prepared to start his route. WTOP-Radio first reported that Malvo would take responsibility for the shooting.

Muhammad, on death row for a Virginia sniper shooting, is on trial in Montgomery County for six killings during the October 2002 shootings that left 10 dead and three seriously injured in the Washington area. The trial will begin a fourth week on Monday.

Ballistics evidence conclusively links the Bushmaster to four of these six Montgomery County victims, Dandridge said. Bullet fragments removed from the bodies of two victims are too small to be linked to a weapon, he said.

Assistant State's Attorney Katherine Winfree asked him to point out the bullet holes on the bloodstained clothing worn by these victims, federal employee James L. Martin and landscaper James "Sonny" Buchanan. Buchanan's undershirt was stained crimson with his blood.

A liquor store employee in Montgomery, Ala., who was killed in September 2002, also was shot by the Bushmaster, Dandridge said.

As the prosecution protested, Muhammad demanded that the Bushmaster be brought into the courtroom when he cross-examined Dandridge. Muhammad has represented himself since he dismissed his lawyers after they declared that he was too mentally ill to stand trial. Three standby lawyers assist him.

"I'm not asking for it for myself," Muhammad said, explaining that he wanted Dandridge to do a demonstration with the weapon. He grew annoyed when he thought that the bolt had been removed and then when Judge James L. Ryan refused to let a padlock be removed from the rifle. The lock prevents the rifle from being taken apart.

Muhammad cross-examined Dandridge for more than three hours, asking him technical questions about firearms. He asked about the possibility of ballistics evidence being confused when weapons are taken apart and reconfigured. The 11 victims were shot with bullets marked by all parts of the Bushmaster, Dandridge said.

Muhammad also spent a significant amount of time cross-examining FBI agent Lora J. Gioeni. She said his mitochondrial DNA -- genetic material taken from the body of a cell -- matched the DNA in a hair in a duffel bag at the last sniper shooting. The DNA did not match Malvo's, Gioeni said. She cautioned that this type of DNA is not unique, and that Muhammad's relatives could have the same DNA.

julie.scharper @baltsun.com