Ashley Warren was a villainess from "Billy the Kid", the Season 1 finale of Sue Thomas: F.B.Eye (airdate May 18, 2003). She was a student at George Washington University and a member of the Gamma Pi Tau sorority.
The episode's events reveal that Ashley and her friend, Connie, attended a rave where they met fellow students Billy Marshall and Adam Davis, the former of whom was a recovering drug addict. Being attracted to Billy, but finding him "uptight", Ashley decided to secretly drug Billy with some of the Ecstasy she got from Connie. The evil Ashley then went about slipping the ecstasy into Billy's drink while Connie was talking to him (presumably as a distraction), later taking some of the drug herself.
Unbeknownst to the girls, however, the ecstacy Connie had bought from dealer Raymond Burke was a bad batch, with the drug causing Billy to non-fatally shoot Judge Kendall (who he was working for as part of his goal of attending law school) before having to be hospitalized himself. After Billy professed that he hadn't taken any drugs at the rave he and Adam went to, his friend Jack Hudson and the rest of the FBI team investigated, learning about Billy's encounter with Ashley from Adam.
After using Ashley's name and sorority to track her down, Jack and Sue Thomas went to the sorority house to question Ashley. But upon arriving, the agents were told a shocking revelation: Ashley had died that morning of a drug overdose, with Connie confessing to Jack and Sue how she'd helped Ashley drug Billy the night of the rave, serving as Ashley's posthumous villainous reveal.