The brother of a Santa Rosa man killed by alleged Asian Boyz gang members testified Monday about the event prosecutors said led up to the slaying — his own kidnapping and torture.

Terry Au, 27, took the stand in the trial for four men accused of killing Vutha Au, 24, in a Blind Beach parking lot in 2008.

In a voice that cracked with emotion, Au recounted his Oct. 1, 2007 abduction, which he said occurred after he tried to stop selling drugs for a family member of one of the defendants.

Au said he was beaten for five hours by assailants who burned his face with cigarettes, choked him and demanded $5,000. They threatened to chop off his fingers with a garden tool and put them on ice so he could buy them back for $1,000 a piece.

"I was scared of being killed," he testified under questioning from prosecutor Traci Carrillo.

Instead of mutilating his hands, they let Au go. He went to police the next day and the men were arrested, charged and eventually sent to prison.

But before they could be brought to trial, prosecutors believe the four defendants grabbed Au's brother on May 2, 2008, drove him to the secluded parking lot near Jenner and shot him nine times.

Prosecutors said he was killed by Preston Khaoone, 26, Quentin Russell, 28, and brothers Sarith Prak, 25 and David Prak, 23, in reprisal for his brother's cooperation with police.

The four men were arrested the same day after witnesses described their car, which was seen leaving the beach. They were all charged with first-degree murder in association with a street gang and face life sentences if convicted.

Two juries are hearing the case — one to consider evidence against Khaoone and the other to weigh the fate of Russell and the Praks.

Security was tight for Au's courtroom appearance. His entire family had been in a witness relocation program since 2007. It was unclear if he was still living outside the county.

Defense attorneys Monday questioned whether any of the men were connected to a gang.

On cross-examination, Terry Au told David Prak's attorney, Steve Weiss, that he didn't know if Khaoone or his brothers were in Asian Boyz and that he was never threatened with gang violence.

Weiss suggested the underlying dispute about drugs and money was unrelated.

"This was a personal thing, is that right?" Weiss said.