28 March 2008 :

the United States marked its sixth consecutive month with no executions of prisoners, its longest such period since 1982, but experts say the death penalty could make a swift return once questions about lethal injection are resolved. The last execution took place on September 25, when Michael Richard, 48, was put to death for the rape and murder of a woman 20 years earlier. He was executed by lethal injection, the method most commonly used.
Just hours before Richards was pronounced dead, the US Supreme Court announced it would examine the legality of the lethal injection method. The court is considering arguments from several death row inmates, led by a pair from Kentucky, that execution by lethal injection violates the US Constitution, which prohibits "cruel and unusual punishment." According to the Death Penalty Information Center, only one more execution is planned this year, a convict in Louisiana in July, and that is expected to be postponed as well.
When the Supreme Court heard oral arguments on the issue in January, the judges appeared split, with some seeming to lean toward the idea of returning the issue to lower courts for a deeper examination of alternative procedures.