This one is a big deal. It’s impossible to say just where the law will go from here, but it’s clear there will be a lot of cases citing this one in the coming years, both because cell-site location is already a widely-used law enforcement tool, and because the majority opinion has a lot to say about what Fourth Amendment “privacy” might mean now that we all share, often unwittingly, so much information about ourselves with the entities that enable our digital lives.
Timothy Carpenter was convicted of several armed robberies; the jury was informed that tower records showed his cell phone had been in (roughly) the right place at (roughly) the right time for four of them. The records his cell providers gave the government actually included a great deal more data: 12,898 location points over 127 days, for an average of 101 data points per day. Particularly at issue on appeal is the government’s request for seven days of location information covering the dates of those four robberies. Carpenter argued law enforcement should have needed a warrant to, effectively, retroactively follow him around, but the lower courts disagreed.
The Supreme Court now holds that a warrant was required. Its precise holding is limited–it specifically declines to decide whether the result might be different if the data covered fewer than seven days–but the implications are significant.
As you might expect the decision has inspired a great deal of commentary from various experts. Amy Howe is a good place to start. Orin Kerr, who had much to say about the case before the decision, has more to say now. On Point will leave the deep analysis to them, but this decision signals some new limits to two longstanding government-friendly Fourth Amendment doctrines.
First, there’s the third-party doctrine. This is the idea that if you voluntarily share information with an entity other than the government, you’ve lost any expectation of privacy in that information–so if that entity shares it with the government, you can’t complain. This decision makes clear that the third-party doctrine may diminish, but does not necessarily extinguish a person’s reasonable expectation of privacy. So, the fact that you (might) know your cell provider can tell roughly where you are when your phone is on doesn’t necessarily mean you are effectively agreeing that the government can also have that information.
Second, there’s the line of cases saying that a person can’t expect that their movements in public will be concealed from the government. The opinion notes that “[p]rior to the digital age, law enforcement might have pursued a suspect for a brief stretch, but doing so for any extended period of time was difficult and costly and therefore rarely undertaken.” (Slip op. at 12). But, things are different now, and the Court is convinced that the principles underlying the Fourth Amendment require a different analysis. It says cell-site location data is the equivalent of attaching an ankle bracelet to its target, and that “w]hen confronting new concerns wrought by digital technology, this Court has been careful not to uncritically extend existing precedents.” (Slip op. at 20).
As we noted up top, this decision is going to be argued about in great detail in the coming years. If you have a case involving evidence obtained from cell providers, ISPs, or the like, it’s an immediate must-read.