Updated 09/20/11 – 9:05 p.m.

CHICAGO (CBS) – A woman sporting a pony tail and wearing a baseball cap and sunglasses robbed a Chase Bank branch in downtown Chicago on Tuesday morning.

As CBS 2′s Suzanne Le Mignot reports, the woman, described as white, in her 20s, brown hair and about 5-feet, 7-inches tall, entered the Chase branch at 600 North Dearborn around 9 a.m., approached the teller counter, handed the teller a note announcing a robbery and threatened harm if her demands for cash were not met.

Surveillance tape captured this woman robbing a Chase Bank branch in North Dearborn. (FBI)

After getting an undisclosed amount of money, she fled the bank on foot.

LINK: Bandit Tracker Chicago

Chicago FBI spokesman Ross Rice said the only thing unusual about the robbery was the fact the robber was a woman.

There have been at least 75 bank robberies in the metropolitan Chicago area this year. Of those robberies, only two or three have involved women as the actual robber or accomplice.

“Bank robbery among women is on the rise. The stats vary. They’re saying anywhere from five to seven to eight percent increase in women, since 2002,” said Dr. Nancy Zarse, a forensic pshychologist with the Chicago School of Professional Psychology

Zarse said that, for a woman to rob a bank, it’s more about fulfilling a need, than seeking a thrill.

“Sometimes it’s about substance abuse and supporting an addiction, but they’re also saying now it might be linked to the desperation of our financial times,” Zarse said.

The robber’s disguise also didn’t leave much to the imagination.

“The digital surveillance systems that most of the banks employ these days capture almost portrait-like images of bank robbers and even though she had a hat and sunglasses on, if you know this person, if this is your neighbor, your co-worker, a relative, you’re gonna recognize her,” Rice said.

Anyone having any information about this robbery is asked to call the Chicago Office of the FBI at 312-421-6700, or the Chicago Police Department.