SAN MATEO (Map, News) - The Mills High School teacher accused of filming girls as they used a school bathroom has resigned.

The San Mateo Union High School District board accepted David Lista’s resignation during a closed-door meeting Thursday night, according to an attorney for the district.

The 35-year-old had been on paid administrative leave since allegations arose last month that he had stashed a camera above a bathroom stall and filmed students, storing the footage on his classroom computer.

Marlene Sacks, an attorney for the district, was tight-lipped about the board’s decision. She said the school district would not benefit from outright firing an embattled teacher.

“In general, going through the process of a formal termination of a teacher is very long and expensive,” Sacks said.

The San Mateo Union High School District had said it did not want to take action against Lista until charges were officially filed. Superintendent David Miller said he was saddened by news of the alleged tapings, saying all teachers in the district were personally hurt that the children “were betrayed that way.”

“Those kids trust us,” Miller said. “There’s no bigger letdown than that. All the teachers feel hurt by this. ... I know the military feels that way when one soldier goes bad.”

A school technology coordinator stumbled upon the inappropriate images on Lista’s computer while investigating a server backup. School officials contacted police, who later searched Lista’s home and allegedly found hundreds of lewd images and video clips of minors on his personal computer, along with evidence he had also stashed a camera under his classroom desk so he could film students during class, prosecutors said.

None of the footage Lista had captured at the school was distributed, prosecutors said.

Police said they also seized a small amount of methamphetamine at Lista’s home.

Lista, who faces several felony and misdemeanor charges, pleaded not guilty earlier this month.

He has been instructed to steer clear from children, to stay at least 100 yards from all elementary and high schools and to use the Internet solely for job hunting or for sending e-mails to adult members of his family, prosecutors said.

A preliminary hearing has been scheduled for July 29.

maldax@examiner.com