US actress Amy Acker is to guest star on next month\'s season finale of \"Person of Interest,\" TVGuide.com reported Tuesday. Best known for her work in TV\'s \"Dollhouse,\" \"Alias\" and \"Angel,\" Acker will play an attractive psychologist who caters to the rich and powerful, the television news Web site said. The show stars Michael Emerson and Jim Caviezel as a pair of unorthodox do-gooders who use numbers to predict and try to prevent crimes. The series\' first season finale is to air May 17. It has been renewed for next season.