S. Epatha Merkerson (born Sharon Epatha Merkerson) is an American film, stage, and television actress. She has won a Golden Globe, Emmy Awards, a Screen Actors Guild Award, Obie Award, 4 NAACP Image Awards, and 2 Tony Award nominations. She is best known for her role as NYPD Lieutenant Anita Van Buren (1993–2010) on the long-running NBC police procedural drama series Law & Order, as well as the Law & Order TV movie Exiled. She appeared in 390 episodes of the series, more than any other cast member. She has a starring role as Sharon Goodwin on NBC's Chicago Med. She also had a recurring role as Reba (the mail carrier) on Pee-wee's Playhouse, and Ms. St. Marth on the TV series Here and Now. She has appeared in feature films including She's Gotta Have It, Loose Cannons, Jacob's Ladder, Terminator 2: Judgment Day, Random Hearts, Radio, Black Snake Moan, Lincoln (2012), and Peeples. She has also appeared in TV movies including A Place for Annie, A Mother's Prayer, Breaking Through, Lackawanna Blues, and The Gabby Douglas Story.