Police said Sean Lavoie, 26, was armed with a knife when he walked into a convenience store on Cottage Street around 11:30 p.m. Tuesday.
He fled once he got some alcohol and some cash, only to be arrested a short time later.
Officials stated the clerk managed to give a great description. Security video was also used.
Police said Lavoie was found a couple of streets away and was arrested. He's now charged with robbery.