Turns out, there really was somebody on the other end of the line.

The "cell phone bandit," who robbed four Northern Virginia banks without missing a conversational beat, was talking to her boyfriend, who was acting as her lookout and getaway driver outside each bank, according to court records and law enforcement officials.

Candice R. Martinez, arrested early yesterday in Centreville, and the boyfriend, Dave C. Williams, told investigators that they planned and carried out each of the Wachovia Bank holdups, according to authorities.

Martinez, 19, a community college student from Santa Fe, N.M., was perhaps the nation's best-known fugitive after police identified her as the woman in the nationally broadcast surveillance video of a Nov. 4 holdup in Ashburn. While looking for Martinez, police targeted Williams, also 19, and picked him up Monday night at an apartment in the Fairfax City area.

Williams, a former Wachovia Bank employee, told investigators that he and Martinez plotted each robbery, starting with an Oct. 12 holdup in Vienna, court records say. Martinez said she walked in, handed over a box with a note demanding $75,000, then stood at the window, chatting on her cell with Williams, who was outside in the getaway car, law enforcement officials said. They made off with $14,700.

Then someone went on a spending spree, according to authorities.

Detectives searching Martinez's Chantilly apartment found a $3,685.21 Circuit City receipt dated Oct. 13 -- the day after the Vienna robbery, according to court records. Police found a Sony personal computer, a digital camera, a computer printer, three Louis Vuitton purses and the box for a T-Mobile cell phone.

Police said they also found two stacks of cash: packets of 30 $50 bills and 20 $100 bills still wrapped in Wachovia bands and dated Oct. 18 and Oct. 19, court records show. Also discovered were a white shirt and black tie, items the cell phone bandit was wearing in her final appearance, Nov. 4 in Ashburn, police said.

But it took two days to find Martinez. Police waited patiently outside her apartment in the Shenandoah Crossing complex on Route 50 in Chantilly. Hoping for help, they released her name to the public Monday, having charged her with robberies in Fairfax and Loudoun counties.

Martinez's father, Phillip Martinez, who lives in Santa Fe, seemed incredulous at his daughter's arrest, saying he had sent her to Northern Virginia to get an education. At first, he did not want to comment about his daughter's arrest.

"It hurts too much right now," he said. But then he added, "She just met a bad guy." Gesturing at several small adobe homes around him, Martinez said: "I almost lost these houses to send her to college. She's supposed to be going to college."

Investigators in Loudoun first connected the four robberies after the Ashburn holdup. They noted that the suspect's description in the Ashburn robbery and three earlier robberies -- in Vienna, the Manassas area Oct. 21 and Burke on Oct. 22 -- was the same: a young woman, thin, short and possibly Hispanic, who demanded money while making little contact with tellers. In three holdups, she carried a box with a note attached. In the fourth, she handed over a note and showed the teller a gun in her purse.

She was carrying the cell phone in all of them.

After arresting Williams in the 9400 block of Lee Highway on Monday, authorities broadcast a lookout for the possible getaway car: A gray 1993 Nissan Maxima. At 3:30 a.m. yesterday, FBI Supervisory Special Agent Ron Chavarro spotted the car as he cruised through a Centreville neighborhood as part of the investigation, FBI spokeswoman Debbie Weierman said.

Chavarro saw two men sitting in the Maxima and ordered them out of the car at gunpoint. Weierman said the men directed the agent to a nearby house in the 14500 block of Picket Oaks Road. Chavarro called Fairfax police for backup. Officers surrounded the house, guns drawn, blue lights flashing, neighbors said. One by one, eight people emerged -- seven men and Martinez, Weierman said. The seven men, and the two in the Maxima, were released.

Martinez was taken to Fairfax police headquarters, where she was interviewed for about six hours. A federal court affidavit filed by FBI Special Agent Timothy S. Pak said Martinez admitted committing the four robberies. Williams made identical admissions, Pak wrote. Martinez and Williams were charged with bank robbery in federal court.

A neighbor in Centreville, Jessica Liu, said that two nights earlier, she saw a young woman pacing on the sidewalk in front of the home where the arrest occurred. The woman was talking loudly into a cell phone, perhaps even arguing, Liu said.

"But I don't know whether it was her, the bank robber," she said. "I'm just very surprised this happened. It's hard to believe because it's such a quiet street."

Liu said that although the neighborhood is relatively peaceful, it was not unusual to hear "lots of commotion" coming from the house, which is two doors from hers. She returns home from work about 11 p.m., she said, and often sees groups of youths outside.

Martinez apparently lived in the Springfield area until recently. A woman who answered the door at the home where Martinez lived with her aunt and uncle declined to comment yesterday. But residents of the 9300 block of Walking Horse Court said they were stunned to learn that Martinez was charged as the cell phone bandit.

One neighbor characterized Martinez as "caring," a young woman loved by the many children who play in the cul-de-sac. "Personally, I think the real story isn't that she robbed a couple of banks," the man said. "She was someone with a good job, a car, going to school, a 19-year-old doing very well. The story is, How did this happen?"

Martinez enrolled at Northern Virginia Community College this fall, spokeswoman Susan Davis said. She took four freshman-level classes at the Annandale campus in subjects such as composition and fitness, Davis said, and she also took one class, "Introduction to Radiography," at the college's Springfield medical education campus.

Martinez planned to pursue a business management degree, Davis said, but has been absent from classes for several weeks. "She wasn't here very long," Davis said. "Nobody really knows her."

In addition to being charged in federal court, Martinez is charged with robbery in state court, but it appears that federal prosecutors in Alexandria will handle her case first. Preparations were being made to transfer her to the Alexandria jail last night. Federal and state prosecutors declined to say yesterday who would prosecute the case first.

Staff writers Sonya Geis, Jerry Markon, Leef Smith and Jamie Stockwell and staff researcher Bobbye Pratt contributed to this report. Geis reported from Santa Fe.

Candice R. Martinez is in custody.