Schwarzenegger in life-or-death choice

The meeting behind closed doors offered defence lawyers and prosecutors 30 minutes each to argue over the fate of the man due to be executed by lethal injection on 13 December for murdering four people in 1979. Clemency would commute his death sentence to life without parole.

Mr Schwarzenegger has said this will be a difficult decision which could be made up to the moment of execution. His staff said he was not expected to rule immediately.

Some believe that if Mr Schwarzenegger grants clemency, it could further undermine his waning support from inside his own party.

"I'd be very surprised if Schwarzenegger would commute the sentence," a Republican analyst, Allan Hoffenblum, said. "But if he did, it would certainly exacerbate his problems."

Before the meeting began, attorney Peter Fleming said: "I'm not going to this hearing with hope. I'm going to this hearing frightened to death. If we fail as counsel, a man dies."

Williams was convicted of killing Yen-I Yang, Tsai-Shai Chen Yang and Yu-Chin Yang Lin in a robbery at a motel the family owned in Los Angeles, and Albert Owens, a shop assistant gunned down in a separate robbery in Whittier.

Last week, the California supreme court declined to reopen the case, amid allegations that shoddy forensics had connected Williams to at least three of the murders.

The federal courts, including the US supreme court, have also ruled against Williams, who was convicted and sentenced to death in 1981.

During a conference call with reporters, Mr Fleming said that if clemency were denied, there would not be much of a case to bring to the federal courts, where he said that he would have to demonstrate that Williams was innocent.

"We're not in a position to do that," Mr Fleming said.

Los Angeles County prosecutors, the California attorney general, Bill Lockyer, and family members of the four victims have demanded that Williams die and said that the governor should not invoke the state constitution and grant clemency.