A 22-year-old Maili man who told police he fell asleep behind the wheel of his pickup truck began serving a one-year jail term Wednesday for running over and killing a Honolulu police officer at a traffic stop near Ko Olina in 2011.

A state judge sentenced James Dorsey on Wednesday to the maximum penalty for misdemeanor negligent homicide.

Circuit Judge Glenn Kim also ordered Dorsey to immediately begin serving his sentence.

A jury found Dorsey guilty last October of causing the Sept. 13, 2011, death of officer Eric Fontes.

Dorsey did not testify in his own trial. At his sentencing, he apologized for what happened.

"It was an accident," he said. "I’ve learned a lot from it. It’s made me more of a cautious person in life."

Deputy Prosecutor Kristine Yoo said Fontes’ death was preventable. She said Dorsey knew he was tired and falling asleep and had even called a friend to help him stay awake on his drive home.

"All of that should have been an indication to him that he should pull over, but he failed to do so," Yoo said.

Fontes, 45, was among four officers assisting a fellow officer at a traffic stop on Farrington Highway near the Ko Olina offramp. They had parked their police vehicles on the grassy median beside the left, westbound lane of the highway and were standing outside their vehicles.

Dorsey’s pickup squeezed in between the line of police vehicles and concrete barrier, past two other officers, before striking Fontes. Dorsey’s truck then hit one of the police vehicles, which in turn struck officer Herman "Sam" Scanlan.

The jury had also found Dorsey guilty of felony negligent injury for causing the injuries suffered by Scanlan.

Kim threw out that verdict because he said it was inconsistent with the negligent homicide verdict because it found Dorsey guilty of a higher level of culpability for the same act.