The I-unit obtained documents from Long Beach Police Department in California that proved that officers had been using an application for more than four years that destroyed hundreds of thousands of text messages sent while on duty.

The investigation confirmed that senior officers directed staff to use the application, known as Tiger Text, for any communications they didn’t want to have discoverable by attorneys or investigators.

The I-Unit also discovered that the Missouri State Highway Patrol was using a similar application known as Silent Phone. Some of the destroyed messages were communications between officers during the 2014 protests in Ferguson.