A former Chester County teacher faces dozens of charges of possessing and distributing child pornography and was scheduled to turn himself in Wednesday, the state Attorney General's Office said.

Joseph Fortunato, 60, of Lancaster, resigned from his teaching position at Devon Preparatory School on Monday. He has been charged with 20 counts of possession of child pornography, eight counts of distribution of child pornography, and a related charge.

Police investigated an online peer-to-peer sharing network and found the IP address of Fortunato's computer. On April 17, police searched Fortunato's home and found child pornography on a desktop computer and an external hard drive.

Fortunato had taught science, computer science, and mathematics at Devon Prep since 1998. The school, which said it learned of the investigation on April 18, said none of the charges against Fortunato involved students or staff.

The school also said it had never received complaints about the former teacher and was encouraging anyone with information to contact the Attorney General's Office.

"Of immediate and paramount concern is the impact that this news may have on our students," the school said in a statement. Counseling will be available for students and staff, the school said.

Police found another Lancaster County man, 44-year-old Hector Colon-Plaza, through the online network. Colon-Plaza was charged with four counts of possession of child pornography, two counts of distribution of child pornography, and a related offense.

Both cases will be tried in Lancaster County Court. Attorney General Kathleen G. Kane said the arrests were part of ongoing efforts to target the distribution of child pornography.