I've blogged a lot about the recent geofence warrant cases in the Fourth Circuit and the Fifth Circuit, which reached opposite conclusions on whether access to geofence records is a search (and in the latter case, held all geofence warrants unconstitutional). Today the Fourth Circuit announced that will rehear its geofence warrant case, United States v. Chatrie, en banc. Meanwhile, the Fifth Circuit's petition for rehearing is still pending.
While we're at it, it's interesting to ponder an aspect of modern Fourth Amendment litigation in play with these cases. Although the theoretical basis of the litigation is possible suppression of evidence—the defendants have filed motions to suppress—all the uncertainty about the law doesn't mean there's real uncertainty as to who will win. The reason is the good-faith exception to the exclusionary rule, which as a practical matter reserves suppression of evidence for particular violations—typically, ones that were clear ex ante. The scope of the good-faith exception to the exclusionary rule is uncertain, but the exception is at its strongest when courts resolve novel issues of Fourth Amendment law. Even with the panel ruling in Smith, the Fifth Circuit's remarkable decision saying that all geofence warrants are unconstitutional, the government won in the end on the good-faith exception.
This echoes a common pattern these days in caselaw on the Fourth Amendment and digital evidence. As a practical matter, litigation over novel questions of Fourth Amendment law provides opportunities for courts, if they want, to issue optional advisory opinions on the law going forward. In some cases, courts they take the option and issue an opinion that has holdings to guide future courts. But quite often, courts decline to hand down rulings on the law and say, well, whatever the constitution means, there's no remedy under the good-faith exception. This is what has happened in a bunch of the major cases I have blogged about here, such as the Second Circuit's ruling in United States v. Ganias, and the Fifth Circuit's ruling in United States v. Morton. Lots of discussion of critically important questions, and then, ultimately, no answer.
