The driver accused of causing a fatal 2006 collision in Kunia which killed four farm workers was on pain-killing medication at the time of the accident, says his attorney.

John Joseph Szemkow, 47, pleaded no contest today to four counts of misademeanor third-degree negligent homicide and felony failure-to-render aid in an accident involving death or serious bodily injury. He will be sentenced in late June by Circuit Judge Derrick Chan.

Sam King Jr., Szemkow's attorney, told The Advertiser his client had been taking a prescribed pain-killer for about a month leading up to the April 4 accident which killed Aquilina Polendey, 57, and Ana Sacalamitao, 46, of Waipahu, and Lorna Laroco, 53, and Gertrudis Montano, 59, of 'Ewa Beach.

"No doctor told him it could be a problem," King said of the medication prescribed for Szemkow, a disabled veteran.

Szemkow, who police said was overtaking vehicles in a reckless manner on Kunia Road, faces a maximum 10-year sentence for leaving the scene of an accident.

Szemkow hasn't driven since the accident and didn't know he had caused a Ford F-250 pickup truck carrying 12 farm workers to swerve and collide into a cement truck on Kunia Road, said King.

"There's evidence, which we will present at sentencing, that he didn't know an accident had occurred behind him," King said. "He wasn't running away, he just didn't know."

The third-degree negligent homicide charge says investigators do not believe Szemkow intentionally, knowingly or recklessly caused the collision due to extreme negligence. "The accident itself was the result of simple negligence," King said.

Deputy city prosecutor Russell Uehara said Szemkow, a civilian worker at Schofield Barracks, should serve prison time and not be given probation because "he snuffed out the lives of four people."

Szemkow, who turned himself in to the provost (at Schofield) when he learned the suspect vehicle in the accident matched the description of his car, decided to change his plea from not guilty to no contest to avoid having the victims' families endure a trial, King said.