Justice Brett Kavanaugh on Tuesday signaled a possible break with his fellow conservative Supreme Court justices during a dramatic day of oral argument in a high-stakes death penalty case.

The case concerns Russell Bucklew, who was convicted in Missouri on charges of murder, kidnapping and rape, and sentenced to be executed this year. Bucklew has argued that his execution, if carried out by lethal injection, would be cruel and unusual because he has a rare medical condition that would make the procedure excruciatingly painful.

In his questions to Missouri’s attorney, Kavanaugh suggested he was sympathetic to that argument.

“Are you saying even if the method creates gruesome and brutal pain you can still do it because there’s no alternative?” Kavanaugh asked John Sauer, the state’s solicitor general.