The US Supreme Court has ruled that death row inmates can file last-ditch challenges to lethal injections, the means of execution in most US states.
Hill argues the chemicals cause suffering that violates his rights
The unanimous ruling came in the case of Clarence Hill, who argued that the chemicals used would cause unnecessary pain and violate his civil rights.
Hill was strapped down with tubes running into his arms when the Supreme Court halted his execution in January.
Legal battles now seem set over how other death row inmates are executed.
Clarence Hill, 47, received a stay of execution at the very last minute on 24 January this year as he was lying on a gurney waiting for the lethal injection to be administered.
The Supreme Court intervened to allow consideration of whether the combination of chemicals used in lethal injections causes pain, so violating a Constitutional ban on cruel and unusual punishment.
Sodium pentothal - anaesthetic
Pancuronium bromide - paralyses entire muscle system
Potassium chloride - stops the heart
The Supreme Court justices have now ruled that Hill - who was convicted of murdering a policeman in Florida in 1983 - and other inmates can bring challenges after they have exhausted the regular appeals process.
The ruling, written by Justice Anthony Kennedy, said that while Hill and other prisoners can file special appeals, they will not always be entitled to delays in their execution.
"Both the state and the victims of crime have an important interest in the timely enforcement of a sentence," Justice Kennedy wrote.
The ruling only stated that Hill could bring the challenge and did not address whether the method of lethal injection violated the US constitution.
Nevertheless, the 3,370 people on death row now have a way to contest how they are executed, correspondents say.
Lethal injection is used in all the 38 states which permit capital punishment, except Nebraska which requires electrocution.
The standard method is a combination of three chemicals.
Hill had exhausted the normal appeals procedure so he went to court using a civil rights law, claming that his constitutional rights would be violated by Florida's lethal injection.
The Supreme Court's decision renews his bid to have Florida change its chemical combination, the Associated Press news agency reports.
In another ruling, the Supreme Court decided that a Tennessee death-row prisoner can use DNA in an attempt to show his innocence 20 years after he was convicted of murder.
Justice Kennedy said Paul House could proceed with a lawsuit in a federal court claiming his innocence for the murder of a young mother in 1985.
DNA testing revealed that semen found at the murder scene did not belong to House.