MADISON, Wis. (WSAU) - A spokesman for the Democratic party is apologizing for comparing Republican Governor Scott Walker to serial killer Jeffrey Dahmer in three tweets.

Graeme Zielinski deleted the tweets and used Twitter to apologize to Walker and the families of Dahmer’s victims. Zielinski made the social media comments after it was announced last Friday that the John Doe investigation of Walker’s aides was closed.

Top Democrats like party chairman Mike Tate and Milwaukee Mayor Tom Barrett called the tweets inappropriate.