A divided Alabama Supreme Court said the state can execute an inmate with nitrogen gas, a method that has not previously been used carry out a death sentence.

The all-Republican court in a 6-2 decision Wednesday granted the state attorney general’s request for an execution warrant for Kenneth Eugene Smith. The order did not specify the execution method, but the Alabama attorney general indicated in filings with the court that it intends to use nitrogen to put Smith to death. The exact date of the execution will be set later by Alabama Gov. Kay Ivey.

The decision moves Alabama closer to being the first state to attempt an execution with nitrogen gas, although there is likely to be additional litigation over the proposed new execution method. Three states — Alabama, Oklahoma and Mississippi — have authorized nitrogen hypoxia as an execution method but no state has attempted to use it.

Smith was one of two men convicted in the 1988 murder-for-hire slaying of Elizabeth Sennett in Alabama’s Colbert County. “Elizabeth Sennett’s family has waited an unconscionable 35 years to see justice served. Today, the Alabama Supreme Court cleared the way for Kenneth Eugene Smith to be executed by nitrogen hypoxia,” Alabama Attorney General Steve Marshall wrote. “Though the wait has been far too long, I am grateful that our capital litigators have nearly gotten this case to the finish line.”

An attorney for Smith did not immediately respond to an email seeking comment.

Lawyers for Smith had urged the court to reject the execution request.

“The state seeks to make Mr. Smith the test subject for the first ever attempted execution by an untested and only recently released protocol for executing condemned people by the novel method of nitrogen hypoxia,” Smith’s attorneys wrote in a September court filing.