What is the current state of the law on "custodial interrogation" in criminal proceedings?

Miranda admonitions (advising a defendant of his or her right to remain silent, to the presence of an attorney and, if indigent, to appointed counsel) must be given, and a suspect in custody must knowingly and intelligently waive those rights before being subjected to either express questioning or its "functional equivalent." (Rhode Island v. Innis (1980) 446 U.S. 291, 300-301 [100 S.Ct. 1682, 64 L.Ed.2d 297]; People v. Ray (1996) 13 Cal.4th 313, 336.) "By custodial interrogation, we mean questioning initiated by law enforcement officers after a person has been taken into custody or otherwise deprived of his freedom of action in any significant way." (Miranda, supra, 384 U.S. at p. 444.)