The case against the "cell phone bandit" is on hold while local and federal authorities tussle over who gets the privilege of prosecuting her.

Federal prosecutors in Alexandria had told local prosecutors that they wanted to try Candice R. Martinez, 19, on charges of robbing four Northern Virginia banks, all the while chatting on her phone. But prosecutors in Fairfax and Loudoun counties, where three of the heists occurred, said not so fast.

Martinez, a student at Northern Virginia Community College, made her first court appearance yesterday in Fairfax, charged with a holdup in Springfield on Oct. 22. Several hours later, Fairfax prosecutors dismissed the charge, seemingly deferring to the feds.

But Fairfax Commonwealth's Attorney Robert F. Horan Jr. said afterwards that he would still consider charging Martinez with a holdup in Vienna on Oct. 12. And in Loudoun, Commonwealth's Attorney James E. Plowman said he had no intention of dismissing charges against Martinez for a Nov. 4 robbery in Ashburn.

"We have a pretty good case," Plowman said last night. "I don't know why I would just drop it. Our guys did a lot of work. The Fairfax detective and our detective probably did 90 to 95 percent of the work. For other agencies to swoop down and take the credit for it doesn't seem entirely fair."

Paul J. McNulty, the U.S. attorney in Alexandria, said last night that he wants to "proceed with this case in the best interests of justice."

"If that means local prosecution, then that is acceptable," McNulty said. "This was a great team effort by everyone involved.''

A local law enforcement official not connected with the case said the prosecutorial back-and-forth is unusual. "I would think people would be more careful about working things out ahead of time and say, 'We need to figure this out in advance. If we find this lady, what are we going to do,' " said the official. "I guess that didn't happen here."

Martinez and her boyfriend, Dave C. Williams, 19, told investigators they robbed all four Wachovia banks, according to court records. In addition to holdups in Vienna, Springfield and Ashburn, they said they robbed a bank in Manassas area on Oct. 21. Prince William Commonwealth's Attorney Paul B. Ebert said he would not seek his own charges and would allow federal prosecutors to proceed.

Martinez was arrested after tips poured into police when a surveillance video of the Ashburn robbery was broadcast nationwide. While still a fugitive, she was charged with robbery in both Loudoun and Fairfax.

After Williams was arrested late Monday, and Martinez early Tuesday, federal authorities also charged the pair with the first robbery, in Vienna. FBI affidavits allege that both Williams and Martinez confessed to stealing $14,700 from the Wachovia branch in Vienna. Dollar amounts weren't available for the other robberies. Police found $3,500 in cash, wrapped in Wachovia bands, in the pair's Chantilly apartment last Saturday, court records show.

Martinez told investigators she chatted on her phone throughout each of the robberies with Williams, who sat outside each bank as the getaway driver, authorities said. Martinez did interrupt her conversation at least once, to tell a teller in one robbery that "You're taking too long."

Federal agents took Williams to the federal courthouse for arraignment on his federal charge; Martinez went to the Fairfax jail for arraignment on her state charge.

In announcing the dismissal of the Fairfax charge, Horan said, "If the federal government is going to put them all together, that makes a lot more sense than to spend the time charging all four" in three different counties.

But he also said he planned to consult with Vienna police and could still charge the pair with the holdup there. Horan noted that no bank robbery in Fairfax has been prosecuted in federal court in at least 10 years.

In Loudoun, Plowman said, "We're just going to move forward unless someone presents me with a reason not to."

Plowman wondered whether a federal prosecution would get the defendants more time. "Do they have a better case? I don't know," he said.

Images of the robber as she held up a bank without interrupting her cell phone conversation got nationwide exposure and inspired a flood of tips.