WOODLAND, Calif. -- A man earlier arrested on suspicion of drunken driving after a bus wreck that killed nine people will not be charged at this time with DUI, Colusa County District Attorney John Poyner said Tuesday.

Quintin J. Watts was released from Woodland Memorial Hospital on Tuesday and booked into Yolo County jail on suspicion of a parole violation.

Watts, who was behind the wheel when the casino-bound bus crashed Oct. 5 along Lone Star Road near Williams, was later released to the custody of state corrections officials and was taken to Deuel Vocational Institution in Tracy.

A medical test of Watts conducted the night of the crash found no drugs and alcohol in his system, Poyner said.

"At this point I don't know if the bus was defective. I just know he didn't have any drugs or alcohol in his system," Poyner said. "It could be anything from an accident that is very unfortunate or if he committed gross negligence that could lead to manslaughter charges. I don't know if he fell asleep."

Poyner added that his office is now awaiting a final report on the crash from the California Highway Patrol, which may take months to complete.

The CHP is still gathering facts and information before recommending any charges against Watts.

CHP Sgt. Pat Lundreth earlier said Watts was on medication at the time of the crash.

Watts' mother, Chaney Mae Watts, 77, of Stockton, said her family never believed reports that he had been driving under the influence. She said her son fell into a diabetic coma and regained consciousness only a few days ago.

"We're all really sorry that the accident happened," she said. "When they said DUI, it wasn't the boy I know. It wasn't the boy I raised."

Chaney Mae Watts noted that her son had a history of health problems related to diabetes, including a trip to the hospital last spring when he appeared impaired because of low blood sugar.

Chaney Mae Watts said she spoke to her son for the first time since the crash by phone on Sunday.

She said the first words he said to her: "Momma, you know I'm sorry."

The bus, which had more than 40 people on board, was heading to Colusa Casino at the time of the crash