We're getting season 7 on TV starting from April 2nd and the channel that airs CSI is promoting the show like mad. lol. Anyways they showed a clip extracted from an interview in which Marg talked about the idea of Catherine getting drugged in BTK 1. She said the idea was hers and it came from real-life experiences she'd heard about. Anyway it was the bartender who drugged Catherine. He was paid to do that. I wasn't sure about it until I saw this clip. I guess no matter how careful Catherine was, she couldn't avoid it since it was the bartender.
Btw, it's Catherine's birthday! I know she's just a fictional character, but heck, HAPPY BIRTHDAY CATH! <3