WASHINGTON (AP) – Supreme Court Justice Brett Kavanaugh seems open to the arguments of a Missouri inmate in Kavanaugh’s first death penalty case. The new justice could hold the key to the outcome.

The high court heard arguments Tuesday over inmate Russell Bucklew’s claim that his rare medical condition could result in severe pain during lethal injection.

Kavanaugh is seemingly the tie-breaking vote in Bucklew’s case. That’s because his eight colleagues split 4 to 4 in January over whether to allow Bucklew’s execution to proceed. Justice Anthony Kennedy provided the fifth vote to spare Bucklew. Kavanaugh replaced Kennedy, who retired in July.

Bucklew says a tumor in his throat is likely to rupture and bleed in a lethal injection execution.

He is on death row for a 1996 murder.