A Chicago-area trucker charged in a deadly crash in western Nebraska is challenging the findings of his preliminary hearing.

Josef Slezak is charged in Cheyenne County with four counts of manslaughter and five counts of vehicular homicide.

Authorities say his rig slammed into stalled traffic on Interstate 80 near Potter on Sept. 9. The truck hit a car driven by Christopher Schmidt, of Gaithersburg, Md. The car was pushed into another car that was carrying Schmidt's pregnant wife and their two children. The family was killed.

Prosecutors believe Slezak traveled virtually straight through from Milwaukee to western Nebraska before the accident.

Defense attorney Kelly Breen argues the case isn't strong enough to justify sending it to trial. A hearing is set for Nov. 7.