State v. Dykes
In State v. Dykes, 163 Ariz. 581, 583, 789 P.2d 1082, 1084 (App. 1990), the Court explained the roles of the three branches of government in the enforcement of criminal laws:
The legislature possesses the power to define the acts which constitute crime and the power to prescribe punishment for those acts.
The executive branch also possesses important powers in this area.
The decision of what charges, if any, will be filed, and the discretion to proceed or not to proceed after the criminal action has been commenced, properly reside in the executive branch.
The prosecutor may decide which charges to bring and whether to assert any mandatory sentence-enhancing allegations.
The judiciary too has its role.
"When the jurisdiction of a court has been properly invoked by the filing of a criminal charge, the disposition of that charge becomes a judicial responsibility. "
Sentencing discretion--the choice of a penalty within the range fixed by legislation--is part of the judiciary's responsibility. Id. at 583-84, 789 P.2d at 1084-85.