Yesterday, in United States v. Diaz-Castaneda, the Ninth Circuit had some interesting dicta in an otherwise-routine Fourth Amendment decision. The dicta touches on a topic that law professors have long been very interested in, so I thought I would flag it.
The facts of the case are simple. A police officer saw a truck driving on the highway, observed its license plate number, and then ran a computer check of the plates and learned that the registered owner of the truck had a suspended license. The officer saw that the driver of the truck matched the description of the owner of the truck, so he pulled over the truck. The issue in the case was whether the officer’s viewing the plates and running the computer check was a Fourth Amendment “search” of the driver that occurred without probable cause and was therefore unlawful.
In an opinion by Judge Fisher, the court concluded that no search occurred: the license plates were in plain view, so the officer did not search or seize anything by seeing the tags. This is clearly right in light of cases like New York v. Class. But then the court did something unusual; it adopted parts of a framework from a 6th Circuit dissent suggesting that license checks could be searches in some cases because they might retrieve particularly sensitive information.
In Diaz-Castaneda, the Ninth Circuit concluded that the license check in this particular case was not a search, but that other checks might be searches in some cases:
[T]here is no indication that license plate checks in Oregon result in the retrieval of information that