THE BRONX - Police have released the sketch of a man who they say raped a woman at knifepoint in Mott Haven.

According to investigators, the 21-year-old victim was followed into her building at the Patterson Houses on 143rd Street early Sunday morning. They say he flashed a knife, threatened to kill her and forced her into a stairwell.

The suspect is described as a black man in his 20s with a bump on his left cheek. He's about 5 feet 7 inches tall, and was wearing a black-hooded sweatshirt and a Yankees hat at the time of the alleged assault.