The suit alleges that the social workers who interviewed the accused kidnapper and killer about three months before his arrest 'knew that (Christensen) satisfied the criteria of a high-level threat of harm to others.' URBANA — The estate of Yingying Zhang is suing two social workers at the University of Illinois Counseling Center for wrongful death and negligence in their care of her accused kidnapper and killer, Brendt Christensen. read more