Two men and a teenage boy could face up to nine years in prison after a random attack on two men in Novato who turned out to be police detectives in street clothes, authorities said.

The alleged assault continued even after the detectives identified themselves as such, said Sgt. Bruce Baker of the Marin County Major Crimes Task Force. The incident might have been a gang initiation ritual for the boy, he said.

"They just picked the wrong car," Baker said.

The suspects - Oscar Chacon, 21, of Novato; Bryan Scott Granados, 18, of San Rafael; and Shane Casey Agueros, 16, of San Rafael - were scheduled to appear in Marin Superior Court on Friday to answer charges of assault on a peace officer, battery on a peace officer, resisting police and battery.

Agueros was charged as an adult, said Deputy District Attorney Linda Witong. The three suspects are also charged with committing the crimes as part of a street gang association.

The incident occurred last Friday afternoon in Bel Marin Keys, where Scott Harrington, a detective with the county narcotics task force, and Patrick Eddinger, an officer with the Twin Cities Police Department, were stopped at a traffic light in an unmarked car. Harrington was driving.

A black sedan carrying five people, its stereo blaring, pulled up next to the detectives' car, Baker said. When the investigators looked over, a youth in the back seat yelled "What?" and then jumped out of the car window to attack the officers' vehicle.

The youth

began pounding on the driver's side window with his forearm and fist. When Harrington opened the door, the boy, later identified as Agueros, punched him in the face.

"It was kind of a melee," Baker said. "The fight went on after they identified themselves."

Chacon was arrested at the scene by the two detectives, while Granados and Agueros ran away and were arrested about an hour later after sheriff's deputies found them hiding in the area.

The other two people in the car drove off, running over the tip of Harrington's shoe as they raced away, and have not been arrested.

Harrington was not seriously injured, and Eddinger was not injured at all. Neither detective required time off from work.

At the time of the incident, Chacon and Granados were free on bail pending sentencing in a different case. They had pleaded guilty in connection with a gang-related fight in June on Woodland Avenue in San Rafael, and were due to be sentenced Aug. 13.

Chacon and Granados were allowed to post bail pending sentencing over the objections of the district attorney's office, said Deputy District Attorney Aicha Mievis. Now their bail has been revoked.

Agueros' bail is set at $100,000.

"Shane is 16 years old," said his lawyer, Deputy Public Defender Peter Arian. "Based on the discovery I've been given by the district attorney, I believe his case should be handled in the juvenile courts."

Chacon's defense attorney, Carl Gonser, declined to comment.

Granados' lawyer, Jon Rankin, said the police reports show that "no one other than the juvenile had any physical contact with the police."

Read more Novato stories at the IJ's Novato section.

Contact Gary Klien via e-mail at gklien@marinij.com