Baltimore Police obtained an arrest warrant for Kerron Andrews, in 2014, for attempted murder. In an attempt to find him, they used his cell phone. They requested a pen register order from a judge, in the request they mainly expressed the intent to locate him by getting location information, however they never said that they were going to use a Hailstorm (a type of Stingray) to track the cell phone. Not only did they fail to disclose this, they never got a warrant to actually use the device.
A Hailstorm is essentially an IMSI-catcher where it acts like a mobile tower and MITM attacks are conducted on cell phones that connect to it. A big problem is that it’s indiscriminate and ends up scooping up innocent bystanders’ information. It’s no secret that the Baltimore Police loves using Stingrays, Baltimore Sun reports that they “have used the technology 4,300 times since 2007.”
The response to a discovery request asking if police used a stringray was stalled for months until in June 2015, in a hearing right before trial, an investigator testified in court that a stingray was used and that it wasn’t disclosed in any reports. This secrecy