The Supreme Court recently granted cert on two cases about how the Fourth Amendment applies to the search incident to an arrest of a cell phone found on a person arrested.  In textual terms, when is a search of a cell phone incident to arrest constitutionally “reasonable”? In this post, I want to lay out some of the possible Fourth Amendment rules that the Court might consider to answer that question. I’ll start with a basic introduction to the rationales of the search incident to arrest exception.  I’ll then offer a few possible rules the Court might adopt to answer when a cell phone can be searched under the exception.  Next, I’ll turn to possible rules for how broadly a search should extend under the exception if/when such searches are allowed.  In future posts, I’ll offer some thoughts on how the Court might choose among the rules.

I. The Rationales Behind the Search Incident to Arrest Exception

First, some background. The search-incident-to-arrest exception dates back to the common law, and it allows the government to search a person’s pockets and property on their person and near their person upon arrest. The Supreme Court has often struggled with the proper scope of the search-incident-to-arrest doctrine. There are three basic lines of precedent: 1) precedents on how the law applies to a search of the person, leading to United States v. Robinson; 2) precedents for how the law applies to searches of space in a home around the arrestee, leading to Chimel v. California, and 3) precedents for how the law applies to searches of cars incident to arrest when the person was arrested after driving a car, leading to Arizona v. Gant.

In its modern form, the exception has been justified on two grounds. First, a search may be needed to protect officer safety. A person arrested might have a gun or a knife, and the officer needs to take the weapon away. I think everybody gets that rationale, although it’s not really implicated in a cell phone case. Second, the search-incident-to-arrest power has been allowed to gather evidence. This is the important rationale in the cell phone cases. But to make matters complicated, there is some disagreement on the precise nature of this rationale. There are two approaches, one narrower and the other broader.

The narrower view, articulated in cases like Chimel v. California, is that the evidence-gathering rationale is limited to the need to prevent destruction of evidence. If the officers don’t search the person arrested, the thinking goes, he might destroy the evidence before the officers can obtain it lawfully. The broader view, perhaps best articulated in Justice Scalia’s Thornton concurrence (which then influences the majority in Arizona v. Gant), is that the evidence-collection rationale is based on a broader government interest in finding evidence of the crime of arrest. Once the arrest has been made for a particular crime, the thinking goes, a search of the person to find evidence of the crime of arrest becomes reasonable.

II. Possible Rules for When A Cell Phone Search Can Be Allowed Under the Exception

It is helpful to break down the search issues here into three questions: First, when can phones be searched under the search-incident-to-arrest exception at all;  second, how far can the search extend once it is allowed; and third, how broadly does the plain view exception apply for digital searches. Let’s start with the first question, when any search can occur. I think there are three primary possible rules for when any search should be allowed:

  1. Officers can always search the cell phone incident to arrest. This ruled is based on United States v. Robinson, the 1973 case that created a bright-line rule for searching a person incident to arrest. The main argument for this approach is that the rules for physical evidence and digital evidence should be the same. Robinson therefore should continue to apply. We can expect this to be the government’s preferred rule.
  2. Officers can search the cell phone only when there is reason to believe evidence of the crime will be found on the phone. This rule is based on Arizona v. Gant, the 2009 case that applied the exception to the search of a car. The main argument for this approach is that searches of cell phones and cars raise similar issues; both are mobile devices that can store a great deal of evidence, but also can store lots of private things not related to the offense.
  3. Officers can seize the phone incident to arrest, but they cannot search it at all under the exception. This rule is based on Chimel v. California, the 1969 case that applied the exception to space in a home around the person arrested. The main argument for this rule is that once the phone is taken, the evidence inside can be preserved. If the purpose of the exception is to limit the defendant’s ability to destroy evidence, once the phone is seized — and perhaps put in a Faraday bag — the government’s interest is diminished and a warrant should be obtained.

III. Possible Rules for How Far the Allowed Search Can Extend Under the Exception

Once a search is allowed, the next issue is how far the search can extend. There are lots of possibilities, but here are five in particular:

  1. The allowed search can be a complete search of the cell phone without limit. See Robinson’s bright line rule.
  2. The allowed search can be a complete manual search of the phone, but officers cannot use forensic programs to search the phone. Cf. United States v. Cotterman (9th Cir. 2013) (adopting a manual vs. forensic program standard for suspicionless computer searches at the border).
  3. The allowed search can only be for certain kinds of information, such as the kind of information that would be found in a physical search incident to arrest. See United States v. Flores-Lopez (Posner, J.).
  4. The allowed search can be anywhere evidence of the crime might be found, although the search cannot extend where no evidence related to the crime of arrest might be.  See United States v. Ross.
  5. The allowed search can only be for evidence of the crime of arrest. See Gant.

Whatever rule  the Court adopts for how far the search can extend will in turn be informed by a background understanding of what happens next.  If evidence is discovered through a cell phone search, when can that evidence be copied and used in court?   I’m not thinking of the scope of the exclusionary rule — which itself is very much in flux, but is beyond the scope of this post — but rather possible limits such as the plain view exception.  Imagine an officer searches a cell phone that has been seized incident to arrest,  and he searches the phone pursuant to the limits imposed by whatever rule you adopt in Section III above.  If the officer comes across evidence unrelated to the reason justifying the search, can that evidence be used? That question could be answered in a few different ways:

  1. The evidence unrelated to the reason for the search may always be copied and then used in court.   On this thinking, the cell phone has already been seized.  After the phone has been searched and other evidence has been discovered, it can’t be doubly seized; having already been seized in the phone, all the revealed information can be taken, analyzed, and used in court without Fourth Amendment limitation.
  2. The evidence unrelated to the reason for the search may be copied and used in court only if the traditional plain view exception applies.  On this thinking, even though the physical device of the phone has been seized, it’s still a seizure to copy and then use the digital evidence in court.  That seizure needs to be justified by the plain view exception, so the  incriminating nature of the evidence must be immediately apparent before it can be copied and used.
  3. The evidence unrelated to the reason for the search may be copied and used in court only in some specific circumstances or even not at all.  On this thinking, copying the data is a seizure, but the plain view exception should apply more narrowly in the context of digital evidence than it does in the context of physical evidence (see, for example, herehere and here).

So those are some of the rules that might be in play in the cell phone search cases.  In future posts, I’ll consider how the Supreme Court might go about selecting among them.

Full disclosure: I have discussed some of the issues raised in this post with counsel for the Petitioner in Riley. I’m not formally involved in either case, though, and the views in past, present, and future posts remain entirely my own.