WILLIAMS, Calif. -- The California Highway Patrol said Monday it believes the driver of a casino-bound charter bus that crashed and killed eight people was driving under the influence and arrested him.

8 Killed In Crash

Sacramento TV station KCRA reported that Quintin J. Watts, 52, was taken to Woodland Memorial Hospital and was in critical condition on Monday, officials said.

The bus, on its way to a casino on Sunday, overturned, ejecting passengers and crushing others as it rolled into a ditch. Thirty-five passengers were injured.

While the bus had some markings suggesting it belonged to Greyhound, the company said the bus was sold two years ago. The bus has a Texas license plate, but is not registered. A Department of Transportation number on the bus did not turn up any current records.

Greyhound spokeswoman Kim Plaskett said the bus dated back to the 1980s and had no seat belts.

An off-duty Colusa County sheriff's deputy witnessed the crash, the California Highway Patrol said. The bus went off the shoulder of the road, overcorrected and rolled one time.

The bus was pulled back onto the road at about 4 a.m., roughly 10 hours after the crash.

Patrol spokesman Robert Kays said authorities believe the driver was under the influence and arrested him. Officials are investigating whether prescription or nonprescription drugs were involved.

Injured victims were transported to several area hospital. Firefighters used flashlights and infrared sensors to search for possible victims in the tall grass near the bus.

CHP spokesman Robert Kays said the bus had an invalid Texas license plate. He said other registration serial numbers also came up invalid.

As of early Monday morning, authorities had not determined the name of the charter company.