WASHINGTON (AP) - The U.S. Supreme Court stepped into a death-penalty case Monday in which a defendant says his lawyers gave him bad advice by telling him to reject a plea deal that would have spared him a death sentence.

Maxwell Hoffman was convicted in connection with a revenge killing in Idaho and sentenced to death in 1989. He appealed, claiming that he should be allowed to take the deal prosecutors offered anyway.

The 9th U.S. Circuit Court of Appeals agreed. The San Francisco-based appeals court said the state must either release Hoffman or again offer him a plea deal that he originally turned down.

The state appealed to the Supreme Court. The justices said they would decide whether Hoffman is entitled to the plea deal, even though he was later convicted and sentenced in a fair trial.

Hoffman was one of three men charged with the murder of a woman who served as a police informant in a drug deal. Hoffman slit Denise Williams' throat and another man stabbed her. Both men tried to bury her beneath rocks, eventually killing her with a blow from a rock.

The other defendants avoided the death penalty. Hoffman refused to plead guilty on the advice of his attorneys, even though prosecutors told him that if he refused the plea deal they would seek the death penalty.

One of Hoffman's attorneys, William Wellman, told Hoffman he believed that a recent appellate-court ruling in the state of of Arizona showed that Idaho's similar death-penalty scheme was unconstitutional, and that it was a matter of time before the policy would be overturned in court.

But Idaho's death-penalty scheme was not immediately overturned, and on June 9, 1989, Hoffman was sentenced to death.

The appeals court said Wellman made two mistakes that warranted overturning the death sentence.

"We do not expect counsel to be prescient about the direction the law will take," Hon. Harry Pregerson wrote for the three-judge panel. "We nonetheless find that Wellman's representation of Hoffman during the plea-bargaining stage was deficient for two reasons: First, Wellman based his advice on incomplete research, and second, Wellman recommended that his client risk much in exchange for very little."