A Widefield High School teacher accused of sexually assaulting male students was officially charged Monday.

Lee Edward Riddle, 29, faces 18 child sex counts, some alleging a pattern of sexual assault on a child by one in a position of trust — a charge that carries mandatory prison time if convicted.

Riddle, a German teacher at Widefield High since 2009, was arrested in late November after authorities said students alleged he had touched them inappropriately, sometimes in the form of “cup checks” in which Riddle used his hand to strike students’ genitals.

The newly filed charges allege four victims, said prosecutor Michael Fisher.

A judge set a preliminary hearing for Jan. 13.

Riddle is free on $25,000 bond. He remains on paid administrative leave from the school, said school district spokeswoman Samantha Briggs.