How is it legal that they can just beat you in store for stealin

Title. How does it even make any sense that employees and securities can just beat you in the middle of the mall floor. Like I just saw this video of a kid get beat to death and it’s just crazy because I thought you weren’t allowed to touch someone if they were stealing and it’s illegal to beat someone up in the middle of the store just because they stole something. But it happens to people all the time and i don’t get why it’s so legal for certain stores to do this. Like I don’t condone stealing all the time but it’s just crazy to me that it can take a life of someone like it did last week. I couldn’t watch the video till the end because it just broke my heart because the kid was just trying to feed his family and didn’t have anything.