Richard John Grieco Jr. (born March 23, 1965) is an American actor and former fashion model. He is best known for his role as Detective Dennis Booker from the popular Fox series 21 Jump Street (1988-89) and its spin-off Booker (1989-90). He also starred in various movies like If Looks Could Kill and Mobsters (both 1991). Since the height of his fame, he has voiced characters in several video games and appeared as either himself or his 21 Jump Street character in several films and television shows. For the last decade, he has painted in a style he calls abstract emotionalism.