Phoenix, Arizona- A Phoenix high school photography teacher who was looking at porn in class and inadvertently projected it onto a screen could faces criminal charges, police said.

Forrest Martin resigned Wednesday from the staff of Arcadia High School where he had worked for five years.

A Scottsdale Unified School District spokesman said the district is still investigating the case.

But Phoenix police said Friday they are referring the case to the Maricopa County Attorney’s Office for consideration of charges of contributing to the delinquency of a minor and providing obscene materials to a minor, Sgt. Tommy Thompson said.

Martin’s “culpable mental state” at the time he was viewing the pornography in the classroom will be weighed when considering charges, Thompson said.

“By determining his mental state, that will help define his intent,” Thompson said. “Did the individual know he was doing this, or was he recklessly doing this?”

Students in Martin’s photography class complained to school administrators after the class projector began displaying pornography. Martin, 62, told authorities he was unaware his computer was hooked up to the projector.

About 13 students viewed the images for “several minutes,” according to police and a letter the school sent home to parents.