I watched a couple really interesting talks from this past Def Con. In one of the talks, Snoop Unto Them As They Snoop Unto Us, Null Agent points out that all Axon equipment (the company putting tasers on drones) share the same organizationally unique identifier (OUI) and communicate via Bluetooth Low Energy. When you pull your firearm or taser from an Axon holster, it can be set up to signal your bodycam to automatically turn on, for example. So by snooping on the BLE data channels you can look for Axon’s OUI and infer that a law enforcement officer is within your Bluetooth range (max 300ft or so in optimal conditions).
That’s all this script does. If it detects Axon equipment it plays a sound, alerts on your terminal, and logs the MAC address / time of encounter. I run it on my laptop in my living room with a super cheap Bluetooth adapter and I get notified when there are cops outside. Couple this with listening to your local police / public safety radio and you’ll never be surprised by a no-knock again.
I’m not much of a coder, but the method for finding the devices is so simple and easy to repeat that anyone could make an app for it. While I was testing it I was also using Android apps called WiGLE and RF Party that can accomplish basically the same thing. With WiGLE, just adjust the settings to only display Bluetooth devices, and look for anything with a MAC address that starts with 00:25:df or has “Taser International Inc.” in a name field.
I might try to make a simple APK for it, but if someone beats me to it, that’d be rad.