Yesterday, the Sixth Circuit reigned in the "private search doctrine" as applied to computer searches. United States v. Lichtenberger, No. 14-3540. According to Orin Kerr at The Volokh Conspiracy, the opinion creates a circuit split and "may be the next computer search issue to make it to the Supreme Court."
Under the private search doctrine, if a private party conducts a search, without the participation or encouragement of law enforcement, then the private party may show police what was found during the private search. See United States v. Jacobsen, 466 U.S. 109 (1984). Police may not, however, exceed the scope of the private party's initial search without first obtaining a warrant. In fact, an officer must have a "virtual certainty" that the officer's inspection will not reveal more than the private party's search.
In this case, the defendant's girlfriend searched his personal computer and found child pornography. She then contacted police and showed an officer some of the images on the computer. Critically, the girlfriend testified at a suppression hearing that she was not sure whether she showed the officer the same images she saw during her initial search.
As Kerr explains, before Lichtenberger, the Fifth Circuit held that, when a private party views even a single file on a computer disk, the police may inspect all content on the disk without a warrant. The Seventh Circuit followed the same course.
Relying on Riley v. California, however, the Sixth Circuit noted that courts must balance the government's interest in a search against the defendant's privacy interest, and that "the nature of the electronic device greatly increases the potential privacy interests at stake, adding weight to one side of the scale while the other remains the same." This change, the court decided, "manifests in Jacobsen's 'virtual certainty' requirement." The court then held that the officer lacked the necessary certainty here since neither he nor the girlfriend could confirm if he viewed the same files from the initial search. The court thus upheld the suppression of evidence from the search.
The opinion maintains that the Sixth Circuit's approach is consistent with that of the Fifth and Seventh Circuits. Kerr argues that this isn't the case because, although the courts applied the same test, they used "different units" to measure the scope of the search: the whole device, versus a file- or data-based approach. There is a current petition for certiorari from an Eleventh Circuit decision raising this issue.