She made her television debut in the NBC daytime soap opera Santa Barbara (1988) before landing the leading roles on the short-lived dramas True Blue (1989–1990), and Moon Over Miami (1993).
From 1996 to 1999, she played the leading role of Doctor Samantha Waters in the NBC crime drama series Profiler, for which she received a Saturn Award for Best Actress on Television nomination.
[3][4][dead link] In early 1988, Walker joined the cast of NBC daytime soap opera Santa Barbara, playing Andrea Bedford.
She starred in the 1991 NBC television movie Perry Mason and the Case of the Fatal Fashion as murderer Julia Collier; the devious daughter of Diana Muldaur's character.
[4][5] In 1992, Walker played the female leading role opposite Jean-Claude Van Damme in the science-fiction action film Universal Soldier directed by Roland Emmerich.
[13] Later in 1999, Walker co-starred opposite Steve Zahn in the comedy film Happy, Texas, and played the lead role in the Lifetime television movie, If You Believe.
From 2008 to 2010, Walker had the recurring role as ATF Agent June Stahl, a major antagonist on the FX crime drama series Sons of Anarchy.
[21] In 2011, Walker played the leading role in the Lifetime police drama series The Protector, which revolves around a single mother who struggles to balance her family and professional life as an LAPD homicide detective.
[25] She made her feature scripted film directing and writing debut with Sex, Death and Bowling starring Selma Blair.