That kind of treatment doesn’t typically have the outcome the adult hopes it will. It made life easier for the sheriff deputy tho.
In this case, it reportedly did work - the boy calmed down and apologised, but I would agree doing something like that could have backfired.
But the particular Deputy was a school teacher before he became a police officer - which is why he works as a school resource officer. And he knew the kid. From memory, I also believe that he had the video this photo was taken from deliberately to document what was happening.
It’s true the kid wasn’t that dangerous at eight - but you need to teach these lessons before kids become dangerous. Wait until they are capable of hurting people and you create all sorts of problems.
I’m a teacher myself with specialised training in dealing with kids who are prone to aggression and violence. Doing something like this certainly wouldn’t be my preferred response or my first response, but I can understand it. And if other approaches weren’t working - you can’t let the behaviour continue forever.