The traffic death of a Honolulu police officer in September 2011 was the result of a "perfect storm of circumstances" and not negligence, the defendant’s lawyer told a jury Thursday.

James Dorsey, 22, is on trial in Circuit Court on a charge of negligent homicide in the death of officer Eric Fontes.

Defense attorney Carmel Kwock told the jury in opening statements that Dorsey fell asleep while driving on Farrington Highway.

Deputy Prosecutor Kristine Yoo told the jury that Fontes’ death was avoidable. She said Dorsey knew he was falling asleep behind the wheel of his pickup truck but kept driving.

Fontes, 45, was at a traffic stop with four other officers just before the Ko Olina off­­ramp when he was hit by Dorsey’s truck on Sept. 13, 2011.

Police say the truck took an improbable path between a line of police cars and the concrete median, and past other officers before hitting Fontes. Dorsey’s truck also hit a police vehicle, which in turn struck and injured another officer.