The battle over where to try the Army veteran and the Jamaican teen-ager suspected in the Washington-area sniper slayings turned personal yesterday, with Maryland's U.S. attorney forced to defend himself against complaints that he cut short a police interrogation in order to keep the suspects within federal jurisdiction.

John Allen Muhammad, 41, was talking to police in Montgomery County in the hours after his arrest last Thursday, and investigators had hoped that he might offer information about the chain of shootings that left 10 people dead and three wounded, a state law enforcement official said yesterday.

But the official said the questioning was cut short after Thomas M. DiBiagio, Maryland's top federal prosecutor, told investigators he was under orders from the White House and the Justice Department to ensure that the suspects would remain in federal custody, which required a speedy appearance before a magistrate judge at the U.S. courthouse in Baltimore.

"You're a cop, and you're being told the president of the United States wants this guy to go to Baltimore. What are you going to do?" said the state law enforcement source, who spoke on condition of anonymity.

DiBiagio rejected any suggestion that he had blocked efforts that might have led to a confession, saying in a written statement yesterday that the account of the abbreviated interrogation, first reported in The New York Times, was false and that the police interview ended when Muhammad invoked his right to an attorney.

"At no time did I say that the White House had anything to do with the decision to place John Allen Muhammad in federal custody," the prosecutor said. "Both individuals were questioned throughout the day. There was no indication ... that either of the individuals were yielding any useful information. In fact, the juvenile was not speaking to officials at all."

The conflicting accounts spotlighted the tensions that have accompanied the decision about where Muhammad and Lee Boyd Malvo, 17, will stand trial first. County prosecutors in Maryland and Virginia have filed murder charges against both. But the men are in federal custody, which means Justice Department lawyers will determine where they stand trial.

Justice officials said yesterday that no decision had been made. Investigators continued to gather evidence from crime scenes to determine where the strongest case could be built, as FBI agents arrived in Antigua - where Muhammad and Malvo probably met - to trace their steps and possible connections to a passport fraud scheme.

Montgomery County officials have bristled at the federal government's stepping in to prosecute what they view as a local murder case. Justice Department officials accused county prosecutors of striking back by casting a cloud over DiBiagio's actions.

"The suspect cut off the interview, not DiBiagio," a senior Justice Department official said. "This is shameless. This is embarrassing. It's absolute trash."

Montgomery County State's Attorney Douglas F. Gansler declined to comment yesterday on the Times article and denied being the source for the account. But he disputed a central element of DiBiagio's statement.

DiBiagio said the interrogation of Muhammad ceased about 3 p.m. when Montgomery County Deputy State's Attorney John McCarthy "called my office and informed us that the adult had invoked his right to counsel. At that time, by law, the questioning had to cease and the suspects had to be presented to a federal magistrate judge."

The state law enforcement source said Muhammad had not requested an attorney. Gansler also offered a different account.

"The U.S. attorney's office in Baltimore directed law enforcement that the defendant had to leave Montgomery County by 3 p.m.," Gansler said. "Any call made by Mr. McCarthy to the U.S. attorney's office was by way of confirmation that the defendant was indeed on his way to Baltimore."

DiBiagio has found himself in the middle of other high-profile disputes in his first year on the job as U.S. attorney for Maryland. The Republican appointee has come under fire from Mayor Martin O'Malley, who has accused federal prosecutors of not doing enough to fight gun violence in Baltimore. When the prosecutor's office launched an investigation of a state crime-control office overseen by Lt. Gov. Kathleen Kennedy Townsend, she accused DiBiagio of colluding with her Republican gubernatorial opponent and dismissed his probe as "political garbage."

DiBiagio has sought to carve out a reputation as an independent, hard-charging prosecutor, and he has not shied away from criticism. But the feud over the sniper case presents far higher stakes and closer scrutiny. In the past week, DiBiagio has not returned calls seeking comment and his office took the unusual step of announcing that it would not respond to news media inquiries about the case.

His written statement about the interrogation of Muhammad was carefully drafted to include references to the federal statutes regarding a defendant's detention after arrest and was distributed by the Justice Department's main press office in Washington, which also released a statement from FBI Special Agent Gary M. Bald, who helped lead the sniper investigation.

Bald said he was in "constant contact" with DiBiagio and that "there was never any reference to taking any action as a result of Justice Department or White House pressure or requests. All operational decisions were totally driven by the circumstances of the interviews and not any external pressures."

Muhammad and Malvo were arrested at 3:19 a.m. at a rest stop near Frederick on federal warrants, and were questioned that morning by members of the multiagency task force that headed the three-week manhunt. Investigators viewed those early interviews as crucial.

"When you get a guy at the time of arrest, that is the one time you have to really see if he's going to talk," a law enforcement source who was involved in the interrogations said yesterday.

By all accounts, Malvo offered investigators no help. But the law enforcement source said Muhammad offered signs that he might cooperate: "He was talking. The question is whether he would have ever gotten around to talking about what we wanted to talk about."

With ballistics evidence matching the rifle found in the men's car to several of the shootings, local investigators believed they had enough evidence to charge the pair with murder and hold them in state custody. That meant they could continue questioning for up to another day before the men would have to go before a judge - but they would no longer be in federal custody.

The law enforcement official said investigators did not take a phone call from DiBiagio about 10:30 a.m. When DiBiagio spoke to investigators by phone after 1 p.m., he instructed federal agents to bring the suspects to federal court in Baltimore and referred to orders from the White House and Justice Department, the source said.

DiBiagio's statement said he only cautioned investigators "that federal law requires that a juvenile be brought before a magistrate 'forthwith' and an adult must be brought before a magistrate 'without unnecessary delay.'"

A Justice Department official said DiBiagio showed great patience with local investigators, even after two prosecutors from his office were excluded from roles in the interrogations.

"He said, 'Well, the locals want to do their thing, that's fine,'" the official said. "But by midafternoon, he felt they were treading on thin ice and the judge won't be happy. He told them, 'If you have something good, then keep going. If not, this isn't television.'"

Sun staff writer Kimberly A.C. Wilson contributed to this article.