Josh Wairi, 27, a fifth-grade teacher at the Graham & Parks School, is facing child pornography charges. Officials say he admitted to secretly videotaping and using a camera on his phone to record children changing in a school locker room.

Law enforcement officials executed the search warrant today. Although they had to force their way in, officials said Wairi acknowledged his guilt and confirmed the details of the activities they were investigating.

Wairi, a resident of Beacon Street in Somerville, has been the target of an investigation since July, according to an affidavit by Postal Inspector Scott W. Kelley. The investigation was triggered by AOL reporting an exchange of suspected child porn over its instant messaging service to the National Center for Missing & Exploited Children, who in turn reported it to the Massachusetts Internet Crimes Against Children Task Force.

Wairi formerly taught in Somerville at the Arthur D. Healey School, which teaches students from kindergarten to the eighth grade. He told police he has advertised himself on Craigslist as a babysitter, according to the affidavit.

The affidavit for his arrest is here.

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