I do not know make or model of said drones, but as german News told it they were all of a similar type and of a "professional design", whatever that means. They have to be controlled by someone, and by some certain frequency. Would be best to detect the control signal and then go for it, directional-wise.
Unfortunately, it is not as easy.. because the air is full of control frequencies of all kinds, almost jammed. To be able to control one certain drone, or a swarm, the drone(s) has(ve) to isolate the signal meant for it/them.
So getting hand on one of the drones to find out the frequency and code (often via some Rfid chip) is mandatory
