Treatment for the illness has compromised Hamm's veins and lethal injection would likely cause "cruel and needless pain," according to papers filed by Harcourt, who has represented the convicted killer since 1990.
"What we're litigating right now is the specific venous protocol for lethal injection as applied to Doyle's situation, given his lymphatic cancer, rather than the general cruelty of the drug cocktail in Alabama," Mr Harcourt said.
"Overall, I have to say, it's inhumane to execute somebody who's at the end of his life suffering and battling with cancer."
A KILLER on death row will be administered the lethal injection within months despite suffering a terminal illness that could kill him first.
Doyle Lee Hamm, who was convicted and sentenced to death in 1987 for the robbery-murder of a Cullman County motel clerk, was this week scheduled by the Alabama Supreme Court to die by lethal injection on February 22 next year.
Hamm, 60, has been battling cranial and lymphatic cancer for more than three years.
His lawyer, Bernard Harcourt, who is also a professor of law and political science at Columbia, said the execution would constitute "cruel and unusual punishment" in violation of the Eighth Amendment of the US Constitution.
Treatment for the illness has compromised Hamm's veins and lethal injection would likely cause "cruel and needless pain," according to papers filed by Harcourt, who has represented the convicted killer since 1990.
"What we're litigating right now is the specific venous protocol for lethal injection as applied to Doyle's situation, given his lymphatic cancer, rather than the general cruelty of the drug cocktail in Alabama," Mr Harcourt said.
"Overall, I have to say, it's inhumane to execute somebody who's at the end of his life suffering and battling with cancer."
"Use of one "potentially accessible" vein on Hamm's right hand "would have a high chance of rupturing the vein and being unsuccessful."
Mr Heath, whose research has documented problems in the administration of lethal injections nationwide, concluded that the inability of corrections personnel to inject the drugs properly could "cause Hamm to become paralysed and consciously suffocate" and would be "an agonising death".
Seven per cent of lethal injections in the US between 1890 and 2010 were botched, according to data compiled by the Death Penalty Information Center.
Mr Harcourt asked the court to order corrections officials to disclose how they would successfully complete venous access for the execution, to appoint a special master to oversee a proper medical examination in advance, and to approve an agreed-upon protocol to "humanely achieve lethal injection."
Mr Harcourt has fought to have Hamm's death sentence reduced to life in prison without the possibility of parole, arguing, among other things, that Hamm was sentenced based on an unconstitutional prior conviction and after ineffective assistance of counsel. In 2016, the U.S. Supreme Court declined to hear Hamm's appeal.
In court papers, Mr Harcourt pointed to the case of David Nelson, a death-row inmate in Alabama whose veins were found to be unusable.
Mr Heath examined Nelson and testified on his behalf.
Nelson's execution was stayed in 2003 and he died in prison in 2009.
Alabama is one of many Southern states facing court challenges to their capital punishment methods, with death-row inmates demanding the use of different drugs or tighter procedures to reduce the risk prisoners will suffer excruciating pain during their executions.