Fairfax, Va. ? A judge threw out capital-murder charges Friday against sniper John Allen Muhammad in the slaying of an FBI analyst in a Home Depot parking lot, saying prosecutors waited too long to bring him to trial.

Muhammad is already under a death sentence in another one of the 10 slayings that terrorized the nation’s capital over three weeks in October 2002. That death sentence is unaffected by Friday’s decision.

But the ruling was a defeat for Virginia prosecutors who had hoped to secure a second conviction in case the first was overturned on appeal. Other jurisdictions can still bring Muhammad to trial, including neighboring Maryland, where six of the slayings took place.

The charges were dropped as a result of a Virginia law that requires a trial within five months of a person’s arrest unless the defendant waives the right.

In Muhammad’s case, prosecutors and defense attorneys disagreed over what the arrest date actually was.

Prosecutors said Muhammad was not formally arrested until May 27, 2003, on a warrant issued after he was taken into custody following the sniper spree.

The defense insisted the speedy-trial countdown began no later than Jan. 6, 2003, the day police faxed copies of the indictment to the jail where Muhammad was being held.

Judge M. Langhorne Keith ruled the January fax “constitutes an arrest for speedy trial purposes even if no formal arrest has been made.” That means Muhammad’s original trial date of Oct. 4, 2003, was well outside the five-month window.

Prosecutor Robert F. Horan Jr. said he would ask the judge to reconsider. The judge’s ruling cannot be appealed beyond that.

“It hurts, but there are other states to try him,” said Denise Johnson, wife of bus driver Conrad Johnson, the last person slain in the shooting spree. “Justice will be served.” She was in Maryland at the dedication of a memorial to the victims.

Muhammad attorneys Peter Greenspun and Jonathan Shapiro issued a statement saying the ruling shows the importance of following the law “regardless of the notoriety and terribly serious nature of the case.”

Shapiro added: “It needs saying that we well remember the victims in these cases and the families who suffered so greatly.”

Muhammad, 43, was already convicted and sentenced to death last year for the Oct. 9, 2002, murder of Dean Harold Meyers in neighboring Prince William County. Meyers was gunned down as he filled his tank at a gas station.

Muhammad’s accomplice, 19-year-old Lee Boyd Malvo, was convicted last year in the Franklin killing and sentenced to life in prison. Last week, his lawyer said Malvo would admit guilt to a second of the killings, and drop all appeals of his first conviction.