Bucks County teacher's assistant charged in child pornography investigationYARDLEY, Pa. (WPVI) -- A part-time instructional assistant at Holland Elementary School has been fired after Bucks County authorities charged him in a child pornography investigation. According to investigators, the probe began two weeks ago after the National Center for Missing and Exploited Children submitted cyber tips to the Bucks County District Attorney's Office. A criminal complaint outlines messages authorities say Dingman sent while posing as a child on Snapchat. Detectives say Dingman admitted that investigators would find child pornography on his phone. Police say Dingman had worked as a part-time teacher's assistant in the Council Rock School District and also served as a substitute teacher and soccer coach in other Bucks County districts.