A school bus driver from Mahtowa pleaded not guilty Wednesday to a charge of child endangerment that was filed after a 3-year-old boy was left alone on his bus for three hours with temperatures hovering around zero.

Thomas Mitchell Soderholm, 53, is accused of endangering Ty Stiffarm on Jan. 14 by permitting the boy to be placed in a situation "likely to substantially harm the child's physical, mental or emotional health."

The crime is a gross misdemeanor punishable by a maximum penalty of one year in jail and a $3,000 fine, but under state sentencing guidelines it would result in a presumptive probationary sentence.

Soderholm appeared in State District Court in Carlton with his Duluth defense attorney, Mikkel Long, before Judge Dale Wolf. The defendant waived his right to an omnibus hearing in which the court decides whether there is enough evidence to maintain charges and makes sure that none of the defendant's constitutional rights were violated in the accumulation of evidence.

The defendant has no criminal record and is free without bond until a scheduled May settlement conference.

According to the criminal complaint:

Fond du Lac reservation law enforcement was informed by the Fond du Lac Transportation Department that the boy had been left on Head Start bus No. 31 after being picked up for school on Jan. 14 but not dropped off at the school.

The boy was picked up at his home about 6:55 a.m. that day. About 11 a.m., a Fond du Lac Transportation employee was walking by the Head Start bus and noticed the boy waving and pounding on a bus window.

The reservation's transportation department policy is to have a bus monitor ensure that the bus is empty and no children are left behind. Soderholm told investigators that the bus monitor told him the bus was empty.

The investigation revealed that the bus monitor has some cognitive disabilities that were known to Soderholm. The bus monitor admitted to investigators that despite having a policy requiring him to check the bus he might not have done so on the date the boy was left on the bus.

Fond du Lac Chairwoman Karen Diver told the News Tribune that Soderholm is no longer employed by the reservation.