The US Supreme Court has ruled that it is unconstitutional for judges rather than juries to decide whether to sentence a killer to death.
The court held that a sentence imposed by a judge violates a defendant's constitutional right to a trial by jury. Juries, not judges, must consider all factors that lead to a death sentence, the court found.
The ruling could affect nearly 800 death-row inmates in nine states of the US.
The court made its ruling retroactive, meaning that more than 150 death sentences must be reconsidered immediately.
The court overturned, by a 7-2 vote, its decision in 1990 upholding the Arizona capital sentencing law that gives sole responsibility to the judge to make factual findings necessary to sentence a convicted murderer to death.
