Surveillance video shows the man police say approached a woman walking near 16th Street and Fourth Avenue in Park Slope.
Police say he groped the woman and ran away.
The incident happened around 5 a.m. Wednesday.
The suspect is described as in his 40s, about 5-foot-4 and wearing a red baseball cap and camouflage pants.
Some 20 women were sexually attacked around the neighborhood last year.
Detectives are trying to figure out if this case is linked to any similar incidents in the area last year.
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