Kyron Horman Update: School Groundskeeper Never Saw Stepmom's Truck on Day Ore. Boy Vanished

Kyron Horman (Personal Photo)

PORTLAND, Ore. (CBS/AP) As police appear to be focusing on a white pickup that Kyron Horman's stepmother was driving on the morning the 7-year-old vanished from his Oregon school, a groundskeeper said if the truck was parked anywhere near the school, he would have seen it.

PICTURES: Kyron Horman Missing: New Photos

"It would be impossible for me to either enter the field or exit the field if there was a car parked on the gravel road itself," Dave Stensen told local station KATU. "I mean it would seem to me like I would have remembered, 'Oh gee yeah,' there was a big white truck in my way when I left that day. I would say I'm certain that it wasn't there."

Authorities at a news conference on Wednesday asked for the public's help in tracing the truck's movements and determining who was in or around the vehicle.

Kyron vanished on June 4 following a science fair at Skyline Elementary School in Portland.

Stensen told KATU that he remembers the science fair taking place that morning and that things did not seem particularly chaotic.

"It seemed like just a pretty normal day," Stensen told the station.

Over the weekend authorities distributed a flyer to residents who live near Skyline asking for information about stepmother Terri Horman and one of her friends, and their whereabouts on the day Kyron disappeared.

Terri Horman has not been named a suspect in the case.

Multnomah County Sheriff's spokesman Jason Gates refuses to offer any details about the direction of the investigation.

Anyone with information about the case is asked to contact the Tip Line at 503-261-2847.

Complete Coverage of Kyron Horman on Crimesider.