In the federal drug trafficking case United States v. Lambis, the use of evidence from a cell phone tracker has been controversial. Dubbed the StingRay by its manufacturers, the device mimics the activity of a cell tower.
Phones send data to it and receive signals from it just as they would with a real tower. By measuring signal strength, a StingRay can tell roughly how far away the phone is. And by taking measurements from different places, the phone’s location can be pinpointed.
StingRays allow law enforcement to intercept message contents and metadata from phones and other devices within their range, in addition to location tracking.
Through a warrant served to the the defendant’s service provider, the DEA were able to find unique identifiers tied to his cell phone. With this information they estimated the location, and then used the StingRay to track him down.
Without information gained through the warrant, the DEA wouldn’t have been able to use the Stingray to find Lambis.
After learning his approximate location from the service provider, a DEA technician was able to find his apartment building, and ultimately his apartment, using the StingRay.
After finding Lambis, DEA officers received permission from the occupants to enter and then search the apartment. During this search officers discovered drugs and drug paraphernalia that became evidence in the case.
On July 12, the court approved the defendant’s motion to suppress the evidence, concluding that the search violated his fourth amendment rights.
Judge William H. Pauley III reasoned that the DEA should have obtained a warrant before using the StingRay, writing “Absent a search warrant, the government may not turn a citizen’s cell phone into a tracking device.”
In the order to gran the defense’s motion, the judge cited a supreme court case that concerned the use of evidence obtained through thermal imaging. In that case, Justice Scalia delivered the opinion that—
“[w]here, as here, the Government uses a device that is not in general public use, to explore details of the home that would previously have been unknowable without physical intrusion, the surveillance is a ‘search’ and is presumptively unreasonable without a warrant.”
Judge Pauley, of the district court of southern New York, applies the same logic to the StingRay.
The prosecution supported the DEA’s actions, comparing the StingRay to a drug-sniffing dog, but the court concluded that cell trackers can be used to find anyone; whereas a dog only finds people carrying contraband.