NEW YORK, Dec. 31 (UPI) -- New York City police say an alleged rapist sexually attacked a 16-year-old girl, robbed her and then tied her to a rooftop satellite dish.

"It's particularly horrendous," Police Commissioner Raymond Kelly said. "It's a despicable crime."

Kelly has asked for the public's help in catching the man, described as wearing a white baseball cap, baggy blue jeans, hooded sweatshirt and gray jacket, the New York Daily News reported Saturday.

The teen was walking home from a subway station in the Bronx when the knife-wielding attacker grabbed her from behind and forced her onto the roof of an apartment building, police said.