The federal government filed capital charges yesterday against John Allen Muhammad in the sniper shootings and for the first time detailed evidence in the case, including a brown cotton glove found in his car that appears to be the mate of one found near the scene of a killing in Silver Spring.

The charges, filed under the decades-old Hobbs Act intended to root out organized crime, include 11 of the 14 shooting incidents tied to the sniper attacks, leaving out the three fatal shootings in Virginia. Sources said the complaint purposely excludes those incidents to allow the most flexibility in deciding where to prosecute first. Muhammad already faces charges that carry the death penalty in Montgomery County and two Virginia jurisdictions.

Muhammad's alleged accomplice, John Lee Malvo, 17, appeared at a two-hour proceeding yesterday afternoon in U.S. District Court in Baltimore with his attorney and court-appointed guardian, but cases against juveniles are secret in federal court and neither Justice Department officials nor Malvo's attorney would say what went on there. The New York Times, quoting unnamed senior law enforcement officials, reported in today's editions that the same federal charges brought against Muhammad were brought under seal against Malvo, but that could not be confirmed.

An affidavit filed by investigators in court to support the charges against Muhammad mentions evidence that had not been released publicly. A search of the 1990 Chevrolet Caprice in which Muhammad and Malvo were arrested, the affidavit says, found a laptop computer, walkie-talkies, a global positioning device, bolt cutters and two shooting mittens -- gloves with grips and padding often used in target practice.

The brown glove was found protruding from a hole in the trunk, the government said in the affidavit. Investigators said they believe the men lay on a platform in the trunk and fired at their victims from holes bored through the back of the car. A matching glove was found near the site of the last sniper shooting. The Bushmaster rifle used in the shootings was found behind the car's seat and a .223-caliber bullet also was recovered underneath a paper towel, the court papers said.

It appeared that the men had been living out of the car, the government said.

Muhammad arrived at the federal courthouse in Greenbelt under extraordinary security to hear the 20 charges against him. Seven of the charges carry the death penalty. Muhammad did not enter a plea.

After the brief hearing, Muhammad's attorney, Jim Wyda, urged the public to withhold judgment. "There's so much emotion and passion, which breeds the chance for error and mistakes," said Wyda, a federal public defender. "Mr. Muhammad and his lawyers still trust the system of justice." He noted that Muhammad has never been convicted of a crime.

Muhammad, wearing a cranberry prison jumpsuit, said only a few words to U.S. Magistrate Judge Charles B. Day. "Yes, sir," he replied when asked whether he understood the charges against him. When questioned about whether he was under the influence of drugs or had a mental defect, he replied, "No, sir."

The addition of federal charges to pending counts in Virginia and Maryland further clouds the issue of where the sniper case might be tried first.

The decision ultimately will be made by the Justice Department because both Muhammad and Malvo are in federal custody. Federal prosecutors stressed that despite their decision to bring charges, they will not make a decision until they determine whether the federal government or a jurisdiction in Virginia has the strongest case.

Justice Department officials said they have all but ruled out having the first case brought in the Maryland courts because of limitations in the capital murder law there and the state's historical reluctance to impose the death penalty.

U.S. Attorney General John D. Ashcroft, speaking publicly about the case for the first time, said, "It will be a cooperative decision-making effort that's made with the state and local authorities that cooperated so effectively in the investigation."

He called the sniper shootings, which killed 10 and wounded three and terrified the Washington region for three weeks this month, "atrocious." Ashcroft said the decision about where to try the suspects would be "fact-driven" based on where prosecutors would have the best chance of winning a death penalty conviction. "I believe the ultimate sanction ought to be available here," he said. "It's important we have available the most serious penalties in a setting like this."

The paperwork filed to support the 20 charges against Muhammad lists each of the 13 shootings connected by ballistics evidence to the snipers from Oct. 3 to Oct. 22. An affidavit signed by FBI special agent Christopher R. Braga and Bureau of Alcohol, Tobacco and Firearms special agent Scott E. Riordan outlines in detail how authorities came to arrest Muhammad and Malvo.

Braga and Riordan said the break in the case came with phone calls from someone claiming to be the shooter who referenced wording in notes found at the shooting scenes at a Bowie middle school and in Ashland, Va., and Aspen Hill. Those calls led investigators to a killing on Sept. 21 in Montgomery, Ala. A fingerprint tied to the Montgomery shooting was linked to Malvo, the affidavit said.

Further investigation revealed a link between Malvo and Muhammad, including a witness in Tacoma, Wash., where the pair recently lived, who claimed that Muhammad often called Malvo "sniper."

The affidavit also included the inventory from the search of the Caprice. It does not list a handgun, despite earlier reports in The Washington Post and elsewhere that one was seized.

Most of the counts against Muhammad involve conspiracy and obstructing commerce through extortion and threats of violence -- violations of the Hobbs Act. The affidavit notes that the letter found in Ashland demands $10 million and threatens more violence, specifically against children. He faces the death penalty on seven charges for allegedly using a firearm to commit murder in conjunction with the Hobbs Act violations. He also was charged with firing a gun in a school zone.

The Justice Department charged Muhammad only with the attacks in Maryland and the District and the nonfatal shootings in Virginia. Officials said they decided not to include the fatal Virginia attacks to allow Fairfax County prosecutors to bring their charges. It was done "in an overabundance of caution," one senior official said, to ensure that Fairfax is not precluded from bringing charges.

But law enforcement sources also said that by not including those killings in the complaint, prosecutors leave open the option of bringing a federal case against Muhammad and state charges in Virginia against Malvo or both. Virginia allows the execution of juveniles, while Maryland and the federal government do not.

Over the next several days, top Justice Department lawyers will try to determine the best course of prosecution.

"We're still hopeful that the Justice Department will do the right thing, which would be to prosecute them locally," said Montgomery County State's Attorney Douglas F. Gansler. "Because our citizens were terrorized and paralyzed for three weeks and seven of our citizens were murdered, [we would hope] that it would begin in Montgomery County."

But Justice Department officials said that is unlikely.

Justice officials are looking at Virginia's new terrorism law, which would allow for the death penalty without proof of which defendant fired the fatal shots. However, that law is untested in the courts. They are stacking it up against the Hobbs Act statutes, which similarly would not require the government to prove who was the triggerman. All the people involved in the conspiracy would be culpable, a Justice Department official said.

Some legal experts said the Hobbs Act might be a tortured route to a capital conviction. Relying on interstate commerce issues and extortion and then linking killings to those acts could prove to be more difficult than simply trying the suspects on capital murder charges in state courts, some said.

"From a prosecution perspective, you want to get convictions and you want to get the death penalty," said Ira Robbins, an American University law professor. "Under the laws of any of the jurisdictions, it appears that there's plenty of evidence to secure convictions. But just as trying to get the death penalty under Virginia's terror act is as yet untested, it is still as yet untested if a murder under a Hobbs Act violation can bring the death penalty."

The charges filed yesterday buy the Justice Department time to wait for forensic evidence to be analyzed and assembled. If prosecutors can determine who actually pulled the trigger in individual shootings, a traditional prosecution could be the most effective.

"They can always decide not to prosecute and waive their prosecution in favor of ours," said Prince William County Commonwealth's Attorney Paul B. Ebert, who has obtained a grand jury indictment of Muhammad and has charged Malvo.

David Schertler, a defense attorney in the District and a former federal prosecutor, said the bickering between Virginia and Maryland officials may have spurred the federal action. "The feds are concerned about handing this off to any one jurisdiction, and there's a lack of confidence that any of the localities could handle this as well as the feds could handle it," Schertler said.

Schertler said that if the death penalty is the key issue, authorities should send the case to Virginia or Alabama, where local prosecutors have far more experience with death penalty cases than federal prosecutors, and where jurors have shown a willingness to impose death sentences.

"If I'm the defense attorney for Malvo or Muhammad, I don't want to go to Virginia or Alabama," Schertler said. "I'd rather go into the federal system or to Maryland, because it's tougher to get the death penalty in those forums."

Staff writers Katherine Shaver and Josh White contributed to this report.

A police vehicle carrying sniper suspect John Allen Muhammad returns to the Maryland correctional facility in Baltimore after Muhammad appeared before a federal magistrate judge in Greenbelt and was charged with 20 counts, seven carrying the death penalty. He did not enter a plea.Attorney General John D. Ashcroft meets reporters at the Justice Department in Washington to discuss the case. Deputy Attorney General Larry Thompson, in background, looks on. Ashcroft called the sniper shootings "atrocious."