What is the current state of the law on police interrogation to obtain a confession?

Miranda, of course, involved police interrogation to obtain a confession (Miranda v. Arizona, supra, 384 U.S. 436, 439, 86 S.Ct. 1602, 16 L.Ed.2d 694, 704) and the rule evolved was to protect the constitutional rights of the individual 'against overzealous police practices.' (384 U.S. 436, 444--460, 86 S.Ct. 1602, 16 L.Ed.2d 694, 706.) The evils [39 Cal.App.3d 881] Miranda sought to avoid are well known. (See 384 U.S. 436, 86 S.Ct. 1602, 16 L.Ed.2d 694, 707--715.) The majority opinion gives no guide to what officers should do when confronted with a balancing between the life of a victim and protection of a suspect's constitutional rights.