No, according to two recent Supreme Court decisions – Riley v. California and U.S. v. Wurie. In a companion ruling, the Supreme Court, Chief Justice Roberts, held that: (1) the interest in protecting officers’ safety does not justify dispensing with the warrant requirement for searches of cell phone data; and (2) the interest in preventing destruction of evidence likewise does not justify dispensing with the warrant requirement for searches of cell phone data.
Exception: The Court does not that certain case-specific exceptions my justify a warrantless search of a particular phone such as the need to prevent the imminent destruction of evidence in individual cases, to pursue a fleeing suspect, and to assist persons who are seriously injured or are threatened with imminent injury.
The Supreme Court’s answer to the question of what police must do before searching a cell phone seized incident to an arrest is simple—get a warrant!