During the 1990s, Walker had roles in films such as "Universal Soldier" (1992), "Singles" (1992), "When the Bough Breaks" (1994), "While You Were Sleeping" (1995), "Kazaam" (1996), and "Happy, Texas" (1999). From 1996 to 1999, she played the leading role of Doctor Samantha Waters in the NBC crime drama series "Profiler", for which she received Saturn Award for Best Actress on Television nomination. She returned to television with a role in the HBO drama series "Tell Me You Love Me" (2007), and later played villainous Agent June Stahl in the FX crime drama, "Sons of Anarchy" (2008–2010). Walker also had the leading role in the short-lived Lifetime police drama series "The Protector" in 2011. During Seasons 4 and 5 (2014 and 2015) of "Longmire", she played Dr. Donna Monaghan, a therapist treating veterans who is the title character's love interest.