WASHINGTON -- The Supreme Court waded deeper into the death penalty debate Monday with a case that could overturn 800 death sentences nationally and another case seeking extra appeals for the condemned.

Death sentences in nine states could be affected by the court's ruling in the case of Timothy Stuart Ring, convicted of killing of an armored car driver during a robbery eight years ago.

The court is expected to decide by summer whether a defendant's constitutional right to a jury trial means that only a jury can make the crucial determinations that result in a death sentence. Currently, although juries are responsible for deciding guilt or innocence, judges decide the sentence in Arizona and eight other states.

The case, said Ring's lawyer Andrew Hurwitz, raises "the basic constitutional principle ... that before you're handed over to the state, for the state to impose whatever punishment it can, that a jury of your peers is afforded to you."

Ring's is the fourth death penalty case the court has reviewed in the current term. None of the cases attacks the essential constitutionality of capital punishment, which is imposed in 38 states.

Another inmate appeal

The court signaled its continued interest in the mechanics of the death penalty by agreeing to hear the appeal of Tennessee death row inmate Abu-Ali Abdur'Rahman, whose case has been championed by activists.

The case, which the court will hear next fall, could have far-reaching effects if the justices decide to loosen the rules for when condemned inmates can get new evidence before a judge.

Justices had blocked Abdur'Rahman's execution earlier this month and will now decide whether he can pursue appeals on new developments.

Other courts had ruled that it was too late for Abdur'Rahman to bring up new allegations that the state didn't turn over evidence as it should have, had made misleading statements and had improperly prepared witnesses.

His case returns the court to a subject that has troubled some of the justices: whether poor people facing a possible death sentence are getting good legal help.

One of his government-provided trial lawyers admitted that he did little to prepare for the trial or the sentencing. It was the attorney's first capital case.

His lawyers also relied on information from prosecutors that blood was found on Abdur'Rahman's clothing. The spots were paint.

Last year, Justice Sandra Day O'Connor said it may be time to impose minimum standards for lawyers who handle death penalty cases. Justice Ruth Bader Ginsburg said that in all the eleventh-hour requests for Supreme Court reprieves, she had not seen one in which the inmate had been well-represented at trial.

The court partially addressed the question of ill-prepared death penalty lawyers in a ruling last month that upheld a death sentence for a Virginia man whose lawyer had represented the victim in an unrelated case.

O'Connor was the deciding vote as the court ruled 5-4 that the alleged conflict of interest was not enough to show that Walter Mickens was deprived of his right to an effective lawyer.