Defense lawyer Michael S. Arif argued that the letter, which has not been made public, depicts Malvo's state of mind around the end of July last year, just two months before 10 people were shot dead in the Washington area by a sniper's bullet. It includes him writing that "he was going to explode," Arif said.

But Roush agreed with Fairfax County Commonwealth's Attorney Robert F. Horan Jr.'s contention that the letter was "pure, unadulterated hearsay" - unsubstantiated remarks from someone who cannot be questioned about them.

Defense lawyers said they have not given up trying to get the letter before the jury.

Malvo wrote it to Muhammad's 17-year-old niece, LaToria Williams, while the two men visited Muhammad's family in summer of last year in Baton Rouge, La.

Roush refused to allow testimony about the letter's contents, including Williams' thoughts about the letter. With jurors out of the room, Williams testified that the words scared her, so she gave the letter to her mother.

Steven D. Benjamin of Richmond, president-elect of the Virginia Association of Criminal Defense Lawyers, said the defense may not need that letter in evidence, and that its introduction could backfire on them because it suggests that Malvo was not fully indoctrinated, knew what was going on and understood the danger.

Last week, a Virginia Beach jury sentenced Muhammad to die for last year's Oct. 9 fatal shooting of Dean Harold Meyers, who was gunned down at a Manassas gas station.

Malvo is charged with two counts of capital murder in the fatal shooting of FBI analyst Linda Franklin on Oct. 14 of last year. Franklin was gunned down in the parking lot of a Home Depot in the Seven Corners section of Fairfax County as she stood a few feet from her husband. One count alleges that Malvo committed multiple murders within three years; the other is under Virginia's untested anti-terrorism law, accusing him of scheming to extort $10 million from the government in exchange for ending the shooting spree.

Also yesterday, Earl Dancy Jr., a friend of Muhammad's in Tacoma, Wash., testified that Muhammad took Malvo to a firing range to teach him to shoot and trained him on sniper-like video games. He said he illegally bought a gun for Muhammad and that he helped him try to make fake identifications.

Also, Glen Chapman, a Ferndale, Wash., gunsmith, testified that Muhammad came to ask him in November 2001 if he could cut a gun barrel into sections for his son, so that it could be transported in a small case and then screwed together for reassembly.

"It only works in the movies," Chapman said, explaining that the force of a bullet firing through the weak point in the barrel probably would blow the barrel off.