Centreville — Fairfax County police have charged a special-education teacher at Poplar Tree Elementary with 10 counts of possession of child pornography. He is Robert C. Fenn, 26, of Emerald Chase Drive in Herndon.

Detectives arrested him Tuesday, June 12, at the school, capping a week-long, joint investigation by members of the police department’s Child Exploitation Unit and U.S. Immigration and Customs Enforcement’s Homeland Security Investigations agents.

Fenn had been a substitute teacher with Fairfax County Public Schools since 2009 and was hired full-time last summer. He was just completing his first year at Poplar Tree, where he taught special-ed students in kindergarten through third grade. Following his arrest, the school system suspended him without pay.

“Police have indicated to us that no images of students were found on his computer and school computers were not used,” said FCPS spokesman John Torre. “The principal [Sharon Williams] sent a letter to parents [Wednesday] morning, explaining the circumstances and assuring them that, ‘At this point, we have no reason to believe that any of our students are in any way involved or directly affected.’”