Police say the driver of a casino-bound charter bus that crashed and killed eight people is in critical condition and faces charges of driving under the influence.

The California Highway Patrol is identifying the driver as 52-year-old Quintin Watts of Stockton. Officers say they're investigating whether prescription or nonprescription drugs, or alcohol, were involved in Sunday's crash. They said it could be a combination.

Watts was arrested based on observations a witness made before the crash.

The bus did not have seat belts, the patrol said.

Officers are trying to determine the bus owner, but said based on a preliminary investigation, they're looking into a company called Cobbs Bus Service.