Joshua Hickson, 19, of Malaga was convicted of simple assault in Chelan County District Court, The Seattle Times reported Saturday.

The assault occurred at Wenatchee High School Sept. 8 when Hickson overheard a conversation about a student being allergic to peanuts, the Times reported.

Hickson then put his fingers in a peanut-butter sandwich and smeared it on the classmate's forehead, Wenatchee police said, adding the classmate did not suffer an allergic reaction.

"The incident turned out to be fairly innocuous but could have been fatal," said Wenatchee Police Officer Steve Evitt.

Judge Nancy Harmon said Hickson would have received a longer sentence if not for a court evaluation that concluded he suffers cognitive deficiencies, the Times reported.