Police in Northern Virginia said today they have identified the woman known as the "cell phone bandit" and are looking for her in connection with four bank robberies conducted while using a cell phone.

The Loudoun County Sheriff's Office said the woman is Candice Rose Martinez, 19, of Chantilly, Va., and said arrest warrants have been issued.

"Ms. Martinez is considered to be armed and dangerous," the sheriff's office said in a statement.

Police asked for the public's help in identifying a young, dark-haired woman after bank surveillance video showed her robbing a Wachovia Bank branch in the Ashburn community of Loudoun County on Nov. 4. The video, which was picked up by news media and broadcast nationwide, showed the woman handing a note to a bank teller to demand money while holding a cell phone to her ear the entire time. In that robbery, the robber also showed the teller a firearm in her purse.

Kraig Troxell, a spokesman for the Loudoun County sheriff, said Martinez has lived in the area for about a year and has ties to New Mexico and other parts of the West.

Because of media coverage of the cell phone bandit case, "we received a number of phone calls, and several of the callers named the same name," Troxell said. He said he did not know whether those calls came from Northern Virginia or the Southwest.

So far, Martinez has been charged with the Nov. 4 robbery and a robbery of a Wachovia Bank in Fairfax County on Oct. 22.

She is also a suspect in two other Northern Virginia bank robberies: one in Vienna on Oct. 12, and another in Prince William County on Oct. 21. Those robberies remain under investigation.

Each robbery was conducted while the suspect held a cell phone to her ear. but investigators do not know if she was actually talking to someone -- possibly an accomplice -- or was using the phone as a prop. If the latter, law enforcement sources have speculated, she could have been trying to throw off suspicion by appearing distracted and nonchalant, or she might have been trying to convey the impression that she had backup.

In its statement, the Loudoun sheriff's office urged members of the public who may have seen Martinez or know her whereabouts to contact police. It said police from Fairfax County, Prince William County and the town of Vienna, as well as the FBI, have been working together on the case.

Troxell said investigators are trying to determine if Martinez is still in the area.