Brian Krakow, what have you done?

My So-Called Life star Devon Gummersall guest-stars on Wednesday's Criminal Minds (9/8c, CBS), doing things that would definitely not win Angela Chase over. He plays the latest unsub, Joseph Berzon, a twisted man who is disfiguring women in a myriad of grotesque ways.

"He's a crazy unsub who is doing all sorts of disgusting things to disfigure women's faces, but he doesn't do the same thing to every victim. His ritual is different each time," executive producer Erica Messer tells "Devon is so good and so creepy in it. You will not look at him the same."

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Get a glimpse of Gummersall in action in the exclusive sneak peek above. Criminal Minds airs Wednesdays at 9/8c on CBS.

(Full disclosure: is owned by CBS.)