Vengeance Unlimited - Season 1 Episode 4 Bitter End

The only witness to a murder, Pam Broder, is stalked by the killer from inside the prison through anonymous threat letters. Then the killer is set free. Chapel decides she needs protection, and enlists the help of Chuck Bidally, an ex-cop. But the killer, Hix, soon discovers that he's followed by Chapel, and evades him. He makes an attack on Pam, but in reality it's only a warning to Chapel. The warning turns into reality when Pam's brother is framed, and then killed - inside the police station. Chapel seems always to be two steps behind, and Hix has only begun his mission...