Jurors returned guilty verdicts Thursday against four Asian Boyz gang members on trial for murdering a Santa Rosa man in retaliation for his brother's testimony in another gang-related case.

The decision from the rare double jury brings to a close a more than 4-year-old case that began with the March 2008 abduction of Vutha Au, 24, outside a downtown pool hall and ended with his death in a hail of bullets in a secluded beach parking lot near Jenner.

Jurors convicted his killers — Preston Khaoone, 26, Quentin Russell, 28, and brothers Sarith Prak, 25, and David Prak, 23, all of Santa Rosa — of first-degree murder, kidnapping and gang participation, setting them up for life in prison without parole at their July 27 sentencing.

"The jury absolutely got it right," prosecutor Traci Carrillo said after the verdicts were read by the court clerk. "I'm very proud of the justice system."

The defendants showed little emotion. The verdicts were announced first for Russell — the alleged shooter — and the Prak brothers. About 15 minutes later the clerk read findings for Khaoone.

Khaoone, who prosecutors said was the ringleader, stared at his feet. He was believed to have organized the killing as payback to Au's brother, Terry, who prosecutors said was identified by the gang as a "snitch."

Jurors, who deliberated about a day for Khaoone and two days for the other three, declined to be interviewed as they left the court. One woman told prosecutors in the hallway she was scared by revelations about Santa Rosa's violent gang underworld.

According to testimony in the trial that began April 30, Au and his family were victims of that ruthlessness.

Trouble stretched back to 2007, when Terry Au was abducted and tortured by Asian Boyz members, including two of Khaoone's brothers, after he refused to continue selling drugs for them.

He testified against the men at a preliminary hearing and was placed with his family in a witness relocation program.

But Vutha Au returned to Santa Rosa to visit friends. On March 1, 2008, gang members learned he was in town and staged his abduction in a series of text messages to each other.

After being delivered by two other defendants to a billiards hall on Mendocino Avenue, Au was placed in a blue Honda Accord with Khaoone, Russell and the Praks and driven to the Blind Beach parking lot.

Prosecutors said he likely pleaded for his life along the way and was gagged with his own socks. He was eventually forced from the car and hunted down by Russell, who shot him nine times in the head, back and limbs.

The men fled but were arrested a short time later after police received a description of their car leaving the area. The gun, a pair of gloves and Russell's T-shirt were found along the route.

There were no eyewitnesses so prosecutors relied on cellphone records at trial. Jurors also heard testimony from Terry Au and a jailhouse informant who said Khaoone confessed the killing to him.