Modifies provisions relating to trial procedures for murder in the first degree

HB 1134 changes how first-degree murder trials are conducted in cases where the death penalty is not waived. It requires a two-stage trial: first determining guilt, then deciding punishment. If the jury finds the defendant guilty of first-degree murder but doesn't select the death penalty (due to factors like intellectual disability, lack of aggravating circumstances, or mitigating evidence outweighing aggravation), the sentence defaults to life imprisonment without parole, probation, or parole eligibility except by governor's action. The bill also defines "intellectual disability" for legal purposes and applies to offenses committed on or after August 28, 2001.