"I could tell there was a lot of discipline but a lot of passion," Malvo said. "There was a bond there that I hadn't seen before or experienced."

Love for Muhammad
Later, he said, Muhammad took him in and started calling him "son." He started learning about black nationalism and the Nation of Islam.

"Did you come to love Mr. Muhammad?" the prosecutor said.

"Yes," he answered.

Malvo went on to describe their move to the United States and Muhammad's desperate search for his children after their mother was awarded custody.

He used the same calm voice to describe their plan: "There was going to be six shots, six slayings a day for 30 days."

Then, he said, they were planning to implement "Phase 2," using explosives to blow up schools, school buses and hospitals.

Eventually, Malvo described the killings to the jury, never swaying from his clinical tone: "Once I told him he had a 'go,' the shot was taken."

He described seeing one victim slumped over after getting shot and another lying on the ground in a pool of blood.

During his testimony about killing Premkumar Walekar as he was pumping gas into his taxicab, the victim's wife began sobbing loudly and had to be led out of the room.

Malvo lowered his voice but kept talking.

He returned frequently to his complicated relationship with Muhammad.

"He's a man of his word," he said. "If he tells you he's going to do something, it's done."

Once, after a shooting in which "everything was perfect," Malvo said Muhammad told him, "You were calm. I created a [expletive] monster."

Courtroom filled
The day of testimony and the sight of Muhammad cross-examining his former acolyte brought dozens of spectators, who filled every bench in the courtroom.

"I was just rather chilled by his monotone. It didn't seem to have an effect on him," said Barbara McCarthy, an attorney from Rockville who stopped in to see the proceedings. "It was like a classroom recitation. ... What was chilling was the total lack of remorse."

Sylvia Wagner, another attorney who watched yesterday's testimony, said, "I was very upset to think that a human being would go on a killing rampage and describe it as if it was a normal schedule of events. As if he was looking for a place to eat. He's looking for victims. It's so outrageous. It almost makes you shudder about what humanity can do."

Correction: In the originally published version of this story, John Allen Muhammad was incorrectly identified as Lee Boyd Malvo during an exchange in which Muhammad referred to Malvo as "son". The Sun regrets the error.