Wash. Post reports secrecy on the StingRay cell phone scanner has caused a Florida prosecution to unravel

Official silence about use of a StingRay cell tower spoofing device against a defendant has riled the judge in a case in Florida. The judge, Florida Circuit Court Judge Frank Sheffield, ordered the prosecution to produce the device for the defense team to examine, and rather than do so, the prosecution offered the defendant an amazingly sweet plea bargain deal. The Post also has a side-bar on how the StingRay device is thought to work:
~~~~~~~~~~~~~~~
Secrecy around police surveillance equipment proves a case's undoing
The devices grab data from all nearby phone users - suspects and innocents alike.
http://www.washingtonpost.com/world/national-security/secrecy-around-police-surveillance-equipment-proves-a-cases-undoing/2015/02/22/ce72308a-b7ac-11e4-aa05-1ce812b3fdd2_story.html
~~~~~~~~~~~~~~~
How a StingRay works
Surveillance companies are marketing systems to state and local law enforcement agencies that are capable of gathering signals from cellphones to pinpoint a suspect's location. These cell-site simulators, or IMSI catchers, are designed so that neither cellphone users nor carriers detect their use.
http://www.washingtonpost.com/world/national-security/how-a-stingray-works/2015/02/23/b4cfcce2-bb70-11e4-8668-4e7ba8439ca6_graphic.html