WASHINGTON -- Justices on the nation's highest court didn't wait long Wednesday to challenge claims by death row inmate Clarence Hill that aspects of the lethal injection method used in Florida amount to cruel and unusual punishment.

Todd Doss of Lake City, Hill's attorney, was only minutes into his opening statement when Supreme Court justices interrupted to ask whether Hill would find any method of death by lethal injection acceptable.

"I'm willing to bet whatever that alternative is, it would be subjected to a challenge," Chief Justice John Roberts Jr. said.

Justice Antonin Scalia seemed even more doubtful.

"You are pressing it to the point where any pain that can be eliminated must be eliminated," Scalia told Doss. "That's an extreme position."

Hill was convicted of fatally shooting Pensacola police officer Stephen Taylor on Oct. 19, 1982, as Hill and an accomplice exited a downtown bank they had just robbed.

The Hill case is being watched closely by death penalty opponents and advocates because it has important implications for death row prisoners nationwide.

States that use lethal injection for executions do not all use the same method, but a victory for Hill would encourage claims attacking each state's method.

A decision could be issued as soon as June.

If the court sides with Hill, the case probably would end up back in federal court in Tallahassee for full hearings on the questions Hill has raised.

If his claims are ultimately found to have merit, Florida might have to change the way it administers lethal injections. That conceivably could take years to litigate and would delay all Florida executions.

The question before the Supreme Court is whether a lower court erred in dismissing Hill's use of a civil rights statute to force review of the three-chemical combination that Florida's Department of Corrections uses to carry out death sentences.

Hill says the lethal chemical cocktail administered in the death chamber can cause excruciating pain if done improperly and thus violates the constitutional protection against cruel and unusual punishment.

Attorneys for the state so far have successfully argued that Hill has exhausted all the usual death penalty appeals. They say his current claim is repetitive and consequently invalid.

But Florida Assistant Attorney General Carolyn Snurkowski made little headway Wednesday as she fumbled to respond to questions posed by several justices.

"I'm sorry if in any way I was disingenuous," Snurkowski said at one point.

Roberts finally came to her rescue by outlining the constitutional arguments contained in the written brief the state filed with the court earlier.

"That is the core position that the state has taken," Snurkowski confirmed. "I'm sorry if I did not articulate that."

Snurkowski argued that because Hill isn't happy with Florida's lethal injection method, which has been used to execute 16 prisoners, it's his duty to suggest an alternative.

Several justices asked Snurkowski to justify that position, but she was unable to do so.

"This is a death case and not that amusing," Justice Anthony Kennedy said. "Does not the state have a minimal obligation to research whether this is the most humane method?"

In 2000, Florida adopted lethal injection as the state's method of execution after court challenges to electrocutions, which were causing prisoners to burn and bleed excessively.

Hill waited five years to make his lethal injection claim, a delay that several justices questioned closely.

Florida has suspended executions while Hill's case is pending.