« SCOTUS rules 5-4 against finding Double Jeopardy Clause limits prosecutors over severed trials | Main | "Gideon Incarcerated: Access to Counsel in Pre-Trial Detention" »

June 22, 2018

SCOTUS rules 5-4 to extend Fourth Amendment protections to cell-site records in Carpenter

The Supreme Court this morning handed down the biggest criminal case of its concluding Term, Carpenter v. US, No. 16-402 (S. Ct. June 22, 2018) (available here). Though I will leave it to Fourth Amendment experts to unpack the majority opinion (authored by Chief Justice Roberts and joined by all the more liberal Justices) and all the separate dissenting opinions (there are four), my first-cut sense is that this is a "big but narrow" win for criminal defendants and privacy advocates.  Here are a few key passages from the majority opinion leading me to that conclusion:

Given the unique nature of cell phone location records, the fact that the information is held by a third party does not by itself overcome the user’s claim to Fourth Amendment protection. Whether the Government employs its own surveillance technology as in Jones or leverages the technology of a wireless carrier, we hold that an individual maintains a legitimate expectation of privacy in the record of his physical movements as captured through CSLI.  The location information obtained from Carpenter’s wireless carriers was the product of a search....

We therefore decline to extend Smith and Miller to the collection of CSLI.  Given the unique nature of cell phone location information, the fact that the Government obtained the information from a third party does not overcome Carpenter’s claim to Fourth Amendment protection. The Government’s acquisition of the cell-site records was a search within the meaning of the Fourth Amendment.

* * *

Our decision today is a narrow one.  We do not express a view on matters not before us: real-time CSLI or “tower dumps” (a download of information on all the devices that connected to a particular cell site during a particular interval).  We do not disturb the application of Smith and Miller or call into question conventional surveillance techniques and tools, such as security cameras.  Nor do we address other business records that might incidentally reveal location information.  Further, our opinion does not consider other collection techniques involving foreign affairs or national security.  As Justice Frankfurter noted when considering new innovations in airplanes and radios, the Court must tread carefully in such cases, to ensure that we do not “embarrass the future.”  Northwest Airlines, Inc. v. Minnesota, 322 U.S. 292, 300 (1944).

June 22, 2018 at 10:32 AM | Permalink


Congress should decide this question. Are radio signals in the air subject to Fourth Amendment protection? The decision brings up security cameras, which collect light waves in public. These questions are too hard, too value laden for the Court.

Non-detailed thermal imaging (garage roof hotter than expected due to lamps to grow marijuana) was deemed a search by the Supreme Court in 2001. What is the difference between infra red radiation, light waves or radio signals? Not much. They are on a spectrum of wavelengths traveling in public places.

Congress should begin doing its job, and stop being such weasels.

Posted by: David Behar | Jun 22, 2018 10:51:07 AM

David, Congress did decide this question. It decided that searches of cell phone records required a court order supported by reasonable grounds. At least one of the dissents, in passing, argues that the Congressional balancing was permissible. The majority disagreed holding that it needed to be a warrant supported by probable cause.

Posted by: tmm | Jun 22, 2018 2:42:17 PM

I like this outcome as a matter of policy but I believe it entirely wrong as a legal question.

I would have dismissed this on third-party doctrine grounds, sorry but you generally have no protective interest in information you give to another. (I'm not sure that even lawyer-client or the marriage privilege should be understood to be of constitutional import rather than simply statutory exceptions). Even if the information were actually as accurate as GPS rather than general neighborhood; I simply don't see the level of detail of the information having any bearing on the question. That could have even left Kyllo in place since there the information was scooped up by the police rather than being given to someone else first.

Posted by: Soronel Haetir | Jun 23, 2018 11:56:30 AM

SH. The Fourth Amendment refers to reasonable searches. The real meaning of "reasonable" is what Christ would do. There is no historical evidence of his having walked the earth. If he did, he is dead. We are now reading the mind of a dead guy about a modern technology question.

Probable cause probably means a 50.000000000000000001% or higher likelihood of a crime's being committed. Is that true?

In the context of information gathering by the police, what are the definitions of those words, reasonable and probable cause? If they are probabilities, what are they? How are they measured, except by the gut feelings of a judge? This judge is only hearing from one side of the argument, and would be impeached if he tried to get information for himself, "ex parte."

Posted by: David Behar | Jun 24, 2018 5:27:49 AM

Post a comment

In the body of your email, please indicate if you are a professor, student, prosecutor, defense attorney, etc. so I can gain a sense of who is reading my blog. Thank you, DAB