(AP) — A man serving a life sentence for a 1988 explosion that killed six Kansas City firefighters will argue in court that his sentence should be reduced.

U.S. Attorney Tammy Dickinson agreed Wednesday that Bryan Sheppard, who was 17 at the time of the explosion, will be able to argue his case before a federal judge.

Sheppard was one of five people convicted in the firefighters’ deaths in an explosion at a construction trailer fire in south Kansas City. One of the defendants has died. All of them always maintained they were innocent.

Sheppard’s attorney sought the re-sentencing hearing after a U.S. Supreme Court ruling that sentences of life without parole for juveniles violated the Constitution’s prohibition against cruel and unusual punishment.