California Gov. Arnold Schwarzenegger has denied clemency for convicted killer Stanley Tookie Williams, who co-founded the Crips street gang.
Schwarzenegger announced the decision Monday shortly after a federal appeals court refused to block Williams' scheduled Tuesday execution.
The court made its decision about nine hours before Williams is to receive a lethal injection.
Williams met with his attorneys and family members Monday at San Quentin State Prison, and he "still believes there will be some intervention in this process," prison spokesman Vernell Crittendon said.
Sunday, California's Supreme Court rejected an emergency request to stay the execution.
Earlier Sunday, attorney Verna Wefald said the legal team was asking for a stay on the basis that Williams should have been allowed to argue that someone else killed one of the four people he was convicted of slaying.
On Friday, the governor described his looming decision as "a very heavy responsibility."
Williams -- who would turn 52 on December 29 -- co-founded the Crips in Los Angeles and was convicted of killing four people in 1979, but has become an anti-gang crusader while on death row.
He has denounced gang violence and written children's books with an anti-gang message, donating the proceeds to anti-gang community groups.
He said he was trying to prevent young people from making the choices he did, which led to a life of crime and a death sentence.
Celebrities, teachers and anti-death-penalty advocates have spoken on his behalf.
Prosecutors maintain Williams should die for what lead prosecutor John Monaghan called "extremely brutal crimes." Monaghan noted that despite his anti-gang activism, Williams has consistently refused to take part in a debriefing with authorities to provide them potentially valuable information about the Crips gangs.
Williams was convicted of killing a 26-year-old Los Angeles convenience store clerk in February 1979, shooting him twice in the back with a 12-gauge shotgun while the victim was face down on the floor.
Less than two weeks later, jurors concluded, he shot and killed an immigrant Chinese couple and their 41-year-old daughter while stealing less than $100 cash from their motel.
Both cases were handled in a single trial, and Williams was sentenced to death in 1981.