Law enforcement use of one tracking tool, the cell-site simulator, to track a suspect's phone without a warrant violates the Constitution, the D.C. Court of Appeals said Thursday in a landmark ruling for privacy and Fourth Amendment rights as they pertain to policing tactics

The ruling could have broad implications for law enforcement's use of cell-site simulators, which local police and federal agencies can use to mimic a cell phone tower to the phone connect to the device instead of its regular network...

...D.C. Metropolitan Police's use of such cell-site simulator technology to nab suspect Prince Jones in 2013 "violated the Fourth Amendment," the court decided against the U.S. government on Thursday.

"We thus conclude that under ordinary circumstances, the use of a cell-site simulator to locate a person through his or her cellphone invades the person's actual, legitimate and reasonable expectation of privacy in his or her location information and is a search," the court ruling said. "The government's argument to the contrary is unpersuasive."