The now-former director of finance at Devon Preparatory School illegally billed nearly $15,000 to the school’s credit card, authorities said.

John Patrick Sullivan, 46, of Phoenixville, was charged late last month by Tredyffrin police with access device fraud, theft by unlawful taking, and receiving stolen property, according to the affidavit of probable cause for his arrest. He was fired from Devon Prep on May 14, the day his colleagues confronted him with a list of 18 purchases posted to the school’s Bank of America account from May 2018 to late April.

Sullivan said the transactions — which included vacations, vet bills, and online orders of Ambien — could have been made by accident, according to court documents.

Sullivan did not admit to Devon Prep officials to making the purchases, Jennifer Gregory, the school’s director of operations, said Monday. But on May 22, eight days after he was fired, he sent the school a check for about $3,300 — less than a quarter of the $14,617.26 authorities said he spent.

On Monday, Sullivan said, “Yeah, I have no comment.”

His personal website, which says he is looking for a job, states he was Devon Prep’s head junior varsity baseball coach as well as a business instructor. Gregory said Sullivan had nothing to do with the baseball team.

Gregory said the school did not cash the $3,300 check Sullivan sent after he was fired and is seeking full restitution through court.

His preliminary hearing is scheduled for June 26 before Magisterial District Judge Thomas W. Tartaglio.

Sullivan started working at Devon Prep, a private, all-boys Catholic school in Tredyffrin, on Aug. 1, 2016, and taught business classes part-time, Gregory said.

When he became the director of finance and was allowed to use the school’s credit card, Gregory said, he showed “he was pretty good at hiding things."

“He went on a business trip [to San Diego] that was legitimate, but he extended it by three days, which was not legitimate," she said. “And he also included his wife and son in the hotel room charges and the airfare.”

Gregory said school officials became increasingly suspicious as audits turned up more questionable purchases.

Devon Prep’s credit card statements dating to May 2018 showed charges for restaurant and cell phone bills and smaller purchases for food, gas, and monthly parking at Children’s Hospital of Philadelphia, according to the affidavit.

Sullivan denied to his colleagues that he ordered Ambien online, but after he was fired, authorities said, a fourth package of the sleep aid addressed to him arrived at Devon Prep. It was returned.