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 has also starred in various films, including 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. Since 2009, he has also been known as a painter, working in a style he calls abstract emotionalism.