Then adjust the criteria to "people who match a face in the hacked database from their military ID system", if you prefer.

What if they just start wearing a balaclava?

Obviously people trying to hide their identity are evil and thus OK to target.

Good luck dealing with balaclava scarecrows if you just target anyone wearing one.

So just target only the ones that are moving! As a side benefit, you get to make this [0] a reality.

But seriously though, there's a lot of heuristics that can be used for "is a target and not a dummy". Will they be perfect? No. But they don't need to be.

0: https://www.youtube.com/watch?v=mm83FTA89AY

Wearing a balaclava would bump the wearer to the highest priority.

That doesn't work if everyone does it.

How many people are genuinely willing to wear something outside knowing that it will get them killed, and knowing that they would NOT be killed if they did not wear that piece of clothing?

there is already research that can reliably identify individuals by their movement patterns

Yes, there is, but none that can reliably do so within 1-2 seconds from a drone going at a few hundred kph. I doubt that there ever will be, either.

The lack of imagination on things like this baffles me. It’s like the folks who dismissed early digital cameras because of the shitty image quality.

You couple the fast drones with slower surveillance ones at higher altitude to identify possible targets. Or pair them with local security cameras, or the victim’s cell phone pings.

Whose to say the gait databases that these things are pulling from can't be fed garbage though

True! It's a bit like thinking people will suddenly start needing more than 64kb RAM or something.