In 1988, Johnson began starring as Althea Tibbs in the NBC/CBS police drama series "In the Heat of the Night", playing the role through 1993. While appearing on "In the Heat of the Night," Johnson recorded the song "Little Drummer Boy" for the 1991 cast Christmas CD "Christmas Time's A Comin". Providing vocals behind her were country gospel group The Marksmen Quartet. The song was produced by co-stars Randall Franks and Alan Autry. She also appeared in a number of movies at this time, including "Robot Jox" (1989), which featured her only career nude scene, "The Five Heartbeats" (1991), "True Identity" (1991), and "Strictly Business" (1991). On television, she played a leading role in the 1989 film "Dream Date" and starred as Carrie Jones/Carolyn Dimes in the 1990 miniseries "Lucky Chances".