Richard John Grieco Jr. is an American actor and former fashion model. He played Detective Dennis Booker in 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). 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 worked as a painter, working in a style he calls abstract emotionalism.