The director of the state’s child welfare agency who pleaded guilty to stealing money from clients of a Chicago social-service agency 20 years ago has resigned from his post. Department of Children and Family Services Director Arthur Bishop submitted a letter of resignation to Gov. Pat Quinn’s office Wednesday. The letter notes that his background could be a distraction for Quinn in the upcoming election. Bishop pleaded guilty to theft in the mid-1990s for taking money from patients at Chicago mental health center. Quinn’s spokeswoman says the governor immediately appointed a new acting director of the agency. Attorney and social worker Bobbie Gregg was appointed for a 60-day term while a search for a full-time replacement begins.