Is the death penalty a specific incentive to murder? The strange case of Billy Joe Johnson

Billy Joe Johnson got his express wish yesterday, an Orange County jury sentenced him to death (reported in the AP on SFChron website).  The twist is this, Johnson is already serving a forty year to life sentence in California's harsh Pelican Bay prison.  Johnson, a loyal member of a white supremacist prison gang, who sports twin lighting bolt tattoos on his neck (in a fashion once associated with the SS) has been candid that the murder was one of several ordered from prison for the specific purpose of earning Johnson a transfer to San Quentin's death row.

Is Johnson's story credible?  Prosecutors played in court taped statements of Johnson in which, clearly aware that he is being wire tapped, seems to speak directly to his future jurors (from R. Scott Moxeley's reporting in the Orange County News) :

“He ain’t done yet. He’s gonna kill again—oh, man!”

Why?

“I’m a motherfucking, bona-fide, certified, fucking nut fucking case, and if they don’t like it, they can fuck off,” said Johnson, who speaks with a lisp. “You know what I mean? Put that on the fucking front page, you know what I mean? Nut case. Fucking don’t care.”

In a final attempt to bolster his monster image, Johnson told jurors that he is determined to kill members of United Society of Aryan Skinheads, a rival gang.

“I’m on a mission,” he said, winking at the prosecutor.

Does trading life sentence in one of the state's "secured housing units", i.e., supermax prisons, for a cell on San Quentin's death row make sense?  Frighteningly, yes.  Execution is unlikely for at least 20 years (Johnson is already 46 and has spent much of his life in prison).  Death row prisoners get much more lawyer attention and may have better physical conditions.  San Quentin is a prison with far more educational and cultural resources than most California prisons (although death row inmates have little direct access to either).

Perhaps the better question is whether Orange County prosecutors and death qualified jurors are so high on vengeance fumes that they are being manipulated by hardened felon in a gambit that will cost the state millions in court costs over the life of the course of appeals, without gaining one wit of security.