Cell Phone Text Message Search Without a Warrant in California

In People v. Diaz (2011) 51 Cal.4th 84, the California Supreme Court held that "a warrantless search of the text message folder of a cell phone" that occurred about 90 minutes after the defendant's arrest was valid under the Fourth Amendment as a search incident to arrest. (Diaz, supra, 51 Cal.4th at p. 88.) Diaz relied on a series of United States Supreme Court cases that included United States v. Robinson (1973) 414 U.S. 218, which broadly held that after a "'lawful custodial arrest, a full search of the person is not only an exception to the warrant requirement of the Fourth Amendment, but is also a "reasonable" search under that Amendment,'" "whether or not the police have reason to believe the arrestee has on his or her person either evidence or weapons" (the traditional justifications for the exception for searches incident to arrest). (Diaz, at p. 91, quoting Robinson, at p. 235; Chimel v. California (1969) 395 U.S. 752, 762-763.) Diaz reasoned that the determinative issue was "whether the defendant's cell phone was 'personal property . . . immediately associated with his person,'" answered in the affirmative, and held the search was therefore valid. (Diaz, at p. 93.) In Riley v. California (2014) 134 S.Ct. 2473, the United States Supreme Court declined to extend the rule in United States v. Robinson, supra, 414 U.S. 218 "to searches of data on cell phones, and held instead that officers must generally secure a warrant before conducting such a search," effectively overruling Diaz, supra, 51 Cal.4th 84. (Riley, supra, 134 S.Ct. at p. 2485.) The high court explained that neither officer safety nor preservation of evidence justified the search of data on a phone no longer within a defendant's possession: while a cell phone itself might be used as a weapon, "data on the phone can endanger no one," and while a phone's data could be destroyed remotely by a third person, a search probably would not help to prevent that. (Id. at pp. 2485-2487.) Moreover, given the large amount of personal information stored on modern cell phones, the privacy concerns implicated by data searches were far greater than those at play when other physical objects on a defendant's person were searched. (Id. at pp. 2488-2489, 2494-2495.) The court concluded that any concerns about officer safety or the destruction of evidence were better addressed on a case-by-case basis by, for example, the exception for exigent circumstances instead of by a blanket rule authorizing such searches without a warrant. (Id. at pp. 2486-2488, 2499.)