Circuit Judge LeRoy F. Millette Jr. turned aside a plea from Muhammad's lawyers to spare their client's life. He ordered Muhammad executed on Oct. 14, but that date likely will be postponed to allow appeals.
Muhammad, 43, was convicted of capital murder on Nov. 17 and a jury recommended he be sentenced to death for the murder of Dean Harold Meyers at a gas station.
Meyers' death was one of 13 shootings during a three-week span in October 2002.
Muhammad denied any involvement in the killings Tuesday, telling the judge, "Don't make a fool of the Constitution of the United States of America."
"Just like I said at the beginning, I had nothing to do with this, and I'll say again, I had nothing to do with this," Muhammad said.
But Millette said the jury's sentence was supported by law and that "these offenses are so vile that they were almost beyond comprehension."
Larry Meyers, older brother of the victim, testified Tuesday that "Dean meant so much to each and every one of us. I'd prefer to remember the good times."
Defense lawyers had filed a motion Monday arguing that life in prison was the more appropriate sentence to eliminate the disparity between Muhammad's punishment and that of his 18-year-old partner in the killings, Lee Boyd Malvo.
"It offends the Constitution to execute Muhammad and to save Malvo," Muhammad's lawyers wrote, arguing that Malvo was a willful killer who actually pulled the trigger in the Meyers killing. "No rational basis exists to distinguish Malvo from Muhammad."
Malvo, who will be formally sentenced Wednesday in Chesapeake, was given life in prison by the jury in that case. Circuit Judge Jane Marum Roush has no leeway to alter that sentence. In Virginia, judges can accept a jury's sentence recommendation or reduce it, but cannot increase it.
Defense motions filed Friday asked Millette to show leniency, citing Muhammad's lack of a previous criminal background, the effect of an execution on Muhammad's children and the general sanctity of human life.
"We do a disservice to our children when we kill," wrote defense lawyers Jonathan Shapiro and Peter Greenspun. "Whether sanctioned by the state or not, killing is killing. And when the news goes out that John Muhammad was killed with the blessing of the court, the prosecutors, the legislature and the governor, children come to understand that killing is an acceptable thing."
Earlier Tuesday, Millette had rejected a defense request for a new trial for Muhammad. Defense attorneys based their motion on letters that Malvo wrote to another inmate in jail.
Defense lawyers said they were unaware of the letters before trial and said they show Malvo acted and thought independently and was not under Muhammad's influence.
Prosecutors said the letters added nothing to the case, and Millette agreed.
Muhammad's lawyers have raised several issues that will likely be primary points of appeal. First, they argue that under Virginia law only the triggerman in a shooting death can be eligible for the death penalty. The six-week trial never conclusively determined who pulled the trigger in the killings, and much of the evidence suggests Malvo was the shooter.
But Millette sided with prosecutors who argued that the triggerman issue is irrelevant, and that Virginia law allows a death penalty in cases in which a defendant can be shown to be "the instigator and moving spirit" of a killing.
The defense team also argues that a second capital conviction based on a new antiterrorism law is both unconstitutional and improperly applied to Muhammad. The Virginia legislature passed the law after the Sept. 11, 2001, attacks, envisioning al Qaeda-style terrorism.
The law defines terrorism as a crime committed with "the intent to intimidate or coerce a civilian population or influence the policy, conduct or activities of the government ... through intimidation or coercion."
Prosecutors said the circumstances of the October 2002 sniper spree fit that definition of terrorism like a glove. Muhammad and Malvo demanded a $10 million payment from the government to stop the shootings and left notes at shooting scenes promising "more body bags" if their demands weren't met.
The sniper spree led to weeks of terror that left millions in fear. All of the shootings happened outside public places — gas stations, restaurants, bus stops, even a school. The snipers demanded $10 million dollars from the government to stop the shootings, reports CBS News Correspondent Stacy Case.
Authorities in Montgomery, Alabama, have expressed interest in trying both Muhammad and Malvo in a killing there a few days before the D.C.-area spree began. The two have been charged with capital murder in the Sept. 21, 2002, shooting outside a liquor store that killed manager Claudine Parker and critically injured co-worker Kellie Adams.
The final decision on extradition to that state rests with Virginia Gov. Mark Warner. His spokesman, Kevin Hall, has said any decision will not be made until after the sentencings in Virginia.
Greenspun said his client, Muhammad, is not inherently evil.
"I've represented a lot of bad guys," Greenspun said. "I've represented guys that you look them in the eye and see evil. I've spent a lot of time with John Allen Muhammad and that's not him."