https://en.wikipedia.org/wiki/Barrier_troops

There is reference to one battle in China with Japan, Syrian forces involved in crowd control, and everything else here is talking about one of pre-Soviet-Union Russia, the Soviet Union, or post-Soviet Russian Federation practice. Just saying.

I was going to write that retreating is not surrendering, so it wouldn’t be abnormal to shoot Ukrainian soldiers as they try to flee and regroup. But the article is about Russians shooting their own troops.