The Supreme Court (search) ruled Monday that it is unconstitutional to force capital murder defendants to appear before juries in chains and shackles.

Justices, on a 7-2 vote, threw out the conviction of Carman Deck (search), who was shackled in leg irons and handcuffed to a chain around his belly when he faced a Missouri jury that put him on death row.

The high court had already held that people on trial can be shackled only if prosecutors have a strong argument for it. Monday's decision involves sentencing hearings in capital murder cases.

Justice Stephen Breyer (search), writing for the court, said that shackling indicates to juries "that court authorities consider the offender a danger to the community."

"It also almost inevitably affects adversely the jury's perception of the character of the defendant," he wrote.

The decision left room for court personnel to handcuff defendants, but only if they pose a special security risk.

In a dissent, Justices Clarence Thomas and Antonin Scalia said the ruling "all but ignores the serious security issues facing our courts."

"The need for security is real. Judges face the possibility that a defendant or his confederates might smuggle a weapon into court and harm those present, or attack with his bare hands," Thomas wrote for the two.

Deck was convicted of killing James and Zelma Long during a robbery in 1996.

Deck confessed to the execution-style slayings of the couple near De Soto, Mo., in 1996. He went to the elderly couple's door asking for directions, but once inside shot them both twice in the head and stole about $400.

The case is Deck v. Missouri, 04-5293.