Police say it happened around 4:30 p.m. at the Wells Fargo Bank in the 200 block of Green Street.
They say the suspect, 36-year-old Roberto Carlos Varela, entered the bank armed with an unknown type of weapon, approached the counter, and then demanded that everyone get on the floor.
He then jumped over the counter and stole money before fleeing the scene.
Donovan McGeachy was one of several customers inside the bank.
"A guy with a black mask and shades walked in and said 'Everybody get on the ground.' I was thinking this guy has got to be kidding you know," said McGeachy. "He jumped over the counter at the teller. She was just stunned. He proceeded to grab the money. I ran out. I was out of there. I alerted a cop, told him make sure you get down to the bank. It's a robbery."
Varela has been charged with robbery with a dangerous weapon. He's being held at the Cumberland County Detention Center on a $75,000 bond.