Jurors deciding whether to sentence someone to death are entitled to be told that in Arizona, the only alternative is life behind bars, the U.S. Supreme Court ruled this morning

In an unsigned opinion Tuesday morning, six of the justices said it was a mistake for a Maricopa County Superior Court judge not to tell jurors that if they did not sentence Shawn Patrick Lynch to death that he would be sentenced to life behind bars, with no chance of parole. The majority said that had jurors been given that information, they might have decided not to impose the death penalty.

The ruling drew a dissent from Justice Clarence Thomas. Joined by Justice Samuel Alito, Thomas said it was the "sheer depravity'' of the crime that caused jurors to sentence Lynch to death, not the question of whether he might ever get out of prison.

According to court records, Lynch and Michael Sehwani met James Panzarella in March 2001 at a Scottsdale bar. All three went to Panzarella's residence, where he was found tied to a chair with his throat slit. The victim's credit cards were used during the next two days.

Lynch and Sehwani were arrested soon thereafter. Sehwani had Panzarella's credit cards and checks in his wallet. And in the truck and motel room he and Lynch were using, police found the keys to Panzarella's car, a pistol belonging to the victim and a sweater with Panzarella's blood on it.

Blood on Lynch's shoes matched the victim's DNA.

During sentencing, prosecutors argued that jurors should consider the possibility of Lynch being a danger in the future when determining proper punishment. But the trial judge refused to let defense counsel tell the jury that under Arizona law, the only alternative sentence was life without parole.

In Tuesday's Supreme Court ruling, the majority conceded that there was a chance Lynch could be released after 25 years. But the justices pointed out that could happen only through executive clemency. And they said that was not enough of a possibility to let jurors think that if they did not sentenced Lynch to death, he might be released.