They saw a shooter climbing on a roof and were like: hah, that's interesting. And now you're telling me the use some high tech equipment to prevent assassination by drones. Riiiight.
There is no report when you launch a drone, unlike when you fire a mortar. Also, flying a drone is a lot safer and more consistent than trying to fire and aim a homemade mortar.
that is called a missile, not a drone. no consumer uav are doing what you are suggesting, and different uav respond to jamming in a huge variety of ways.
I know most consumer drones land automatically if they lose connection. Anyone that is trying to raw dog a plot like this with an unmodified drone they pulled off the shelf from Best Buy is a special type of idiot.
You're right that it is a stationary target, probably doable by image recognition, even with GPS jamming. Still, bit more sophistication required than just strapping a grenade to a dji.