Mobile Device Search and Seizure
in a Post-Riley World
The latest Supreme Court ruling requires training, policy, and technology for
the proper handling of mobile device evidence.
The United States Supreme Court’s ruling in Riley v. US (573 U.S. ____ ) may not have been much
of a surprise to American law enforcement. Many agencies were already requiring officers to obtain search
warrants before searching mobile devices.
Some state supreme courts had already ruled in favor of warrants for mobile device searches incident to
arrest. While some SCOTUS analysts believed, following oral arguments in April, that the Court might set
a “middle ground” rule, prosecutors, supervisors, and forensic lab examiners were preparing for a brighter line
by requiring officers to seek warrants to be on the safe side.
An old saying in firearms training, “Speed is fine; accuracy is finer,” applies to mobile forensics, too. No
one—including the Supreme Court—disputes the importance of speedy access to critical evidence, especially
in emergencies. As many officers know, mobile device searches can net important evidence that can provide
new leads and possibly even put an offender behind bars within the first few hours of an investigation.
Many state and local jurisdictions had already facilitated warrants for searches incident to arrest by implementing electronic or telephonic systems. These allow judges to return warrants much more expeditiously—
often within minutes—than officers applying in person, especially when in between business hours. Thus,
even a roadside search incident to arrest can take place in a timely fashion.
To that end, the patrol officer or investigator who can articulate probable cause to search a device—
whether seeking a warrant or justifying a warrantless search in exigent circumstances—is in a much better
position to contribute valuable data to an investigation than the officer who asked a forensic examiner to
“give me everything on the device,” a veritable fishing expedition.
Ultimately, rather than limiting law enforcement, the Riley decision frees agencies to deploy mobile data
extraction capabilities across a much wider field of officers. By using policy and training as levers for the
kinds of judgment calls that Chief Justice John Roberts envisioned in his opinion,1 these agencies can reap a
number of benefits:
1. It would reduce the amount of backlog that many labs are experiencing. Many cases involve more than
one digital device, and the storage space—hence the amount of data—found on modern mobile devices
is increasing. Using Riley as leverage to get more officers conducting basic data analysis on “low hanging
fruit” would free lab examiners to focus on more serious cases and technical forensic issues.
2. First responders and investigators in the field would markedly improve their access to actionable evidence in the time they need to complete their investigations. This would be particularly true when a
search doesn’t meet the exigency requirement as outlined in Riley, but officers still don’t have the luxury