The 48-year-old died by injection at 9:11 p.m. Tuesday as relatives of the victims watched from behind glass, separated from the rest of the 27 witnesses at Greensville Correctional Center, south of Richmond.
Muhammad was executed for killing Dean Harold Meyers, who was shot in the head at a Manassas gas station during the spree across Maryland, Virginia and Washington, D.C.
He never testified or explained why he masterminded the shootings with the help of a teenage accomplice. That left questions unanswered about why he methodically hunted people going about their daily chores, why he chose his victims, including a middle schooler on his way to class, and how many victims there were.
Muhammad stepped into Virginia's death chamber and within seconds was lying on a gurney, tapping his left foot, his arms spread wide with a needle dug into each.
"Mr. Muhammad, do you have any last words?" the warden asked. Muhammad, looking calm and stoic, said nothing.
Meyers' brother, Bob Meyers, said watching the execution was sobering and "surreal." He said other witnesses expressed a range of feelings, including some who were overcome with emotion.
"I would have liked him at some point in the process to take responsibility, to show remorse," Meyers said. "We didn't get any of that tonight."
After the first of the three-drug lethal cocktail was administered, Muhammad blinked repeatedly and took about seven deep breaths. Within a minute, he was motionless.
Nelson Rivera, whose wife, Lori Ann Lewis-Rivera, was gunned down as she vacuumed her van at a Maryland gas station, said that when he watched Muhammad's chest moving for the last time, he was glad.
"I feel better. I think I can breathe better," he said. "I'm glad he's gone because he's not going to hurt anyone else."
J. Wyndal Gordon, one of Muhammad's attorneys, described his client in his final hours as fearless and still insisting he was innocent.
"He will die with dignity - dignity to the point of defiance," Gordon said before going inside to watch the execution.
The terror ended on Oct. 24, 2002, when police captured Muhammad and Lee Boyd Malvo while they slept at a Maryland rest stop in a car they had outfitted for a shooter to perch in its trunk without being detected.
Malvo, who was 17 when carrying out the attacks, was sentenced to life in prison without parole for killing Linda Franklin, a 47-year-old FBI analyst who was shot as she and her husband loaded supplies at a Home Depot in Falls Church, Va.
The men also were suspected of fatal shootings in other states, including Louisiana, Alabama and Arizona.
The U.S. Supreme Court turned down Muhammad's final appeal Monday, and Gov. Timothy M. Kaine denied clemency Tuesday.
Muhammad's attorneys had asked Kaine to commute his sentence to life in prison because they said Muhammad was severely mentally ill.
"I think crimes that are this horrible, you just can't understand them, you can't explain them," said Kaine, a Democrat known for carefully considering death penalty cases.
A small group of death penalty opponents gathered on a grassy area near the prison and had a sign reading, "We remember the victims, but not with more killing."
Muhammad was born John Allen Williams and changed his name after converting to Islam. He had been in and out of the military since he graduated from high school in Louisiana and entered the National Guard. He joined the Army in 1985. He did not take special sniper training but earned an expert rating in the M-16 rifle - the military cousin of the .223-caliber Bushmaster rifle used in the D.C.-area shootings.
The motive for the attacks remains murky. Malvo said Muhammad wanted to extort $10 million from the government to set up a camp in Canada where homeless children would be trained as terrorists. Muhammad's ex-wife said she believes they were a smoke screen for his plan to kill her and regain custody of their three children.
Sonia Hollingsworth-Wills, the mother of Conrad Johnson, the last man slain that October, sat in the back seat of a car outside the prison before the execution, which she chose not to witness. But she said she wanted to be there and was counting the minutes until Muhammad's death.
"It was the most horrifying day of my life," she said. "I'll never get complete closure but at least I can put this behind me."
Cheryll Witz, who's father, Jerry Taylor, was fatally shot on a Tucson, Ariz., golf course in March 2002, said she was unhappy that Muhammad didn't say anything before he died. But she said his execution begins a new chapter in her life.
"I've waited seven long years for this," she said. "My life is totally beginning now. I have all my closure, and my justice and my peace."
Associated Press writers Steve Szkotak in Jarratt and Bob Lewis in Richmond contributed to this report.