Police responded to the 4200 block of Wilson Boulevard around 10:30 a.m. on Tuesday.
Investigators say the victim was attacked while she cleaned a bathroom inside a business.
Police have declined to identify the business in an effort to protect the victim.
They say the suspect approached the victim while she was cleaning and asked if he could use it.
When the victim tried to move away from a stall, the suspect pushed inside and slapped her backside.
The victim called for help, prompting the suspect to run off.
However, shortly afterward, the victim was in a nearby closet and tried to block her in again. The suspect reportedly pushed the victim into a closet and tried to lock the door.
Once again, the victim resisted and called for help, and the suspect fled.
The suspect – who was caught on surveillance video – is a black male in his 20s, who stands between 5-foot-10 and 6-foot-2. He weighs about 170 and 190 pounds and has a full beard.
During the incident, he was wearing a white hat, blue jeans, a gray winter coat, and white sneakers.
If you can help police find him, call (703) 228-4208.
Police are also looking for a suspect in an assault that they believe is unrelated.
Tuesday night, police say a woman reported that a stranger attempted to rape her on North Rolfe Street.
Police got the call around 10:45 p.m.
She said she was walking her dog along the North Rhodes Street bridge Over Arlington Boulevard when a man started following her.
She said she started running to get away from him and he chased her, pulled her to the ground, tried to take off her pants.
She says a person nearby heard her screaming and started yelling at the suspect and victim was able to get away.