"The penalty for a defendant found guilty of murder in the first degree, in any case in which one or more special circumstances . . . has been found to be true . . . , who was 16 years of age or older and under the age of 18 years at the time of the commission of the crime, shall be confinement in the state prison for life without the possibility of parole or, at the discretion of the court, 25 years to life. (Pen. Code, 190.5, subd. (b) (section 190.5(b)).) Penal Code Section 190.5(b) has been interpreted to mean "16-or 17 year-olds who commit special circumstance murder must be sentenced to life without parole, unless the court, in its discretion, finds good reason to choose the less severe sentence of 25 years to life." (People v. Guinn (1994) 28 Cal.App.4th 1130, 1141.)