They've released a photo of the suspect.
Police say he followed a woman into a building on Sunday morning, then groped her and tried to steal her handbag before taking off.
It happened at Monroe Street and Catherine Street around 7:50 a.m.
The suspect is described as an Asian man, 25 to 30 years of age, 5'6 to 5'9 in height, medium to thin build, and clean shaven. He was wearing dark pants, a blue waist length jacket and black and white sneakers.
Anyone with information is asked to call Crime Stoppers at 1-800-577-TIPS.
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