Can the police hold a defendant's cellphone seized incident to his arrest until necessary forensic software is developed based upon evidence that the defendant, after his arrest, asked his family to delete its contents?

In Riley v. California, 573 U.S. 373 (2014) the Court held that police must get a warrant before searching a cellphone seized incident to an arrest. But the Court has not yet addressed whether the police can use a defendant’s attempts -post seizure of their cellphone — to protect their privacy-related concerns to justify a search warrant and hold that cellphone indefinitely while waiting for the development of new forensic software. The question presented is: Can the police hold a defendant’s cellphone seized incident to his arrest until necessary forensic software is developed based upon evidence that the defendant, after his arrest, asked his family to delete its contents? ii