McAdams on the Scope-Limited Search Alternative to Riley

Richard H. McAdams (University of Chicago Law School) has posted Riley's Less Obvious Tradeoff: Forgoing Scope-Limited Searches on SSRN. Here is the abstract:

In rejecting the application of United States v. Robinson to the search of cell phones incident to arrest, Riley v. California advanced fourth amendment doctrine by showing that rules and precedents of non-technological settings need not apply to analogous technological settings. Less obviously, however, the case is important for another reason: in requiring a warrant, the Court rejected the governments’ alternative approach permitting a cursory, scope-limited search of cell phones incident to arrest. The Court could have permitted a brief field search of a cell phone incident to arrest, without a warrant, where there is reason to believe that the phone contains useful evidence of the crime of arrest and where police limit their search to the places where such evidence might realistically be found. Some fourth amendment cases distinguish between full-fledged and cursory searches, but here the Court added to the precedent rejecting such a distinction. 

Unfortunately, Riley offers only the most superficial analysis of its decision to reject that approach, despite its being common in the lower courts (and subsequently adopted by the Supreme Court of Canada). In defense of the scope-limited alternative, I offer four arguments.

First, even if one generally prefers simple rules, this context is one where the stakes for privacy and law enforcement are high enough to justify a more complex rule distinguishing scope-limited and full-fledged searches. Second, limited cell phone searches, incident to arrest, are an important component of police work, where persistent promptness in following leads is valuable, even where the value of timeliness falls short of the exigent circumstances exception. By contrast, the warrant requirement can easily produce cell phone searches that are far more intrusive than what a cursory field search would allow. Third, Riley creates an unattractive doctrinal anomaly: the enormous gap between searching private digital and private analog papers incident to arrest; the scope-limited wrinkle narrows that gap. Finally, the refusal to recognize a scope-limited search will pressure lower courts to expand the exigent circumstances exception with undesirable effects beyond the context of cell phone searches incident to arrest.