Prosecutors on Wednesday charged a 62-year-old man who they say broke into an empty school bus more than a year ago and hid there until a class of kindergartners came on board.

Michael Friedrichs, a registered sex offender, faces charges of felony stalking with a victim under 18 years old and stalking, a gross misdemeanor, according to a complaint filed in Hennepin County District Court. He was charged by warrant because he hadn’t been arrested as of Wednesday night.

The incident in question occurred March 6, 2019, when surveillance video showed Friedrichs prying open the doors of an unoccupied school bus parked on S. Nicollet Avenue, according to the complaint.

Friedrichs allegedly rubbed his groin on multiple seat cushions, then hid behind a seat at the back when the bus driver boarded the bus.

He remained out of sight as school staff, chaperones and kindergarten students began boarding the bus after a field trip at the Walker Art Center, the complaint said.

As the bus drove away, Friedrichs stood up and started moving toward the front of the bus, ducking down and standing up several times until a teacher spotted him and alerted the bus driver, according to the complaint. More than once, Friedrichs sat down next to some of the bus riders, including several kindergartners, one of whom started crying, prosecutors allege.

The driver later told police that she remembered feeling “absolutely horrified” and “genuinely afraid” when she realized Friedrichs was on the bus, not knowing whether he was armed.

Prosecutors requested the warrant, citing a history of criminal sexual conduct, including past incidents where he’d masturbated on school buses and convictions for crimes against children, the complaint said. He was convicted in 2011 of fifth-degree criminal sexual conduct for masturbating on a school bus with children on board.