PURDY, Wash. -- A student presenting an essay at Peninsula High School in Purdy on Tuesday morning took out a marijuana joint, lit it, and began smoking it, police said.

Read the essay here. See cell phone video.

According to Pierce County sheriff's detective Ed Troyer, the student smoked the joint during his essay supporting the legalization of marijuana.

He then finished his essay, sat down, finished smoking the joint and then ate the end after it was fully smoked.

The teacher of the class contacted the school resources officer, a Pierce County sheriff's deputy, who found a small residual amount of marijuana on the student, Troyer said.

The student, a 17-year-old junior with a 3.7 grade-point average, was arrested on charges of possession of marijuana by Pierce County deputies and booked into Remann Hall in Tacoma.