A female victim tells police that one man sexually assaulted her while a second man restrained her and threatened her with a knife.
Police have released a sketch of one of the suspects.
He has a dark mole on his right upper lip and was carrying a 6-inch hunting-style knife. the other suspect was wearing a dark blue sox baseball cap and a red t-shirt with a white rhino insignia on the front.
Anyone with information on this attack is asked to contact Chicago police.
