“Desperate Housewives” villain Roger Bart — who plays the show’s pharmacist with a homicidal bent — will join the hit ABC series full-time next season.

Bart stole scenes as the creepy George Williams, a lonely man who develops a crush on one of his customers, Bree Van De Kamp (Marcia Cross). In Sunday’s season finale, Bree’s husband Rex apparently died after — unbeknownst to them — a jealous George tampered with his pills.

Beyond his “Desperate Housewives” gig, Bart will appear this December in the feature version of “The Producers,” reprising his stage role as Carmen Ghia. Bart scored a Tony nom for his Broadway perf in the musical.

Bart also will appear in the indie comedy “I Want Someone to Eat Cheese With,” directed by Jeff Garlin. Thesp’s other credits include “The Stepford Wives” and the CBS sitcom “Bram and Alice.”

In other casting news, Annabella Sciorra (“The Sopranos”) has joined the cast of NBC’s “Law & Order: Criminal Intent,” playing opposite Chris Noth. Sciorra will play Det. Carolyn Barek to Noth’s Det. Mike Logan; together they’ll front 11 episodes of the series’ fifth season.

Duo will alternate with original stars Vincent D’Onofrio and Kathryn Erbe, who will star in the season’s other 11 episodes.

Sciorra received an Emmy nom for her role as Gloria Trillo, Tony’s mistress on “The Sopranos.” She also guested in the series premiere of “Law & Order: Trial by Jury.”

Sciorra’s other credits include “Cop Land,” “What Dreams May Come,” “Reversal of Fortune” and “True Love.” She’ll next be seen in the features “Twelve and Holding” and “Find Me Guilty.”