AZ SB1548

Changes the standard for imposing a death sentence from mandatory ("shall") to discretionary ("may") when aggravating circumstances are found and no substantial mitigating circumstances exist.

Requires the prosecution to prove aggravating circumstances beyond a reasonable doubt during the aggravation phase of sentencing.

Allows defendants to present any relevant information as mitigating circumstances during the penalty phase, regardless of evidentiary rules, with the burden on the defendant to prove mitigating circumstances by a preponderance of the evidence.

Maintains existing lists of aggravating circumstances (10 factors including prior convictions, heinous conduct, victim characteristics) and mitigating circumstances (5 factors including impaired capacity, duress, minor participation, age).

Applies to defendants convicted of first degree murder under specified circumstances, with sentence options ranging from death to life imprisonment or natural life depending on defendant's age at time of offense.