I know a little bit about the people involved in this case, but I can only say there wasn't any history prior to this. The guy jumped at him in the video so I can understand his initial reaction to retaliate, but looks like he let it get personal and went too far. Looks like there may have been some backtalk going on in the video.
The Sheriff's Office too recently (not related to Metro Police) has just installed a new camera system in the detention center which
they used to suspend 3 officers who went too far in the clinic. Either family tipped off sheriff and they checked the video or they caught it as part of an internal investigation which led to them announcing the suspensions.
Either way, I think it's the right call. They need to set examples so that certain people know there are consequences to going overboard on the job. Sadly any position that offers power over other individuals is going to attract certain types of corrupt individuals.
My grandmother (the wife of a career law enforcement officer) used to say that this field attracts two types of individuals... the type who for the right reasons and are
dedicated... and then those who are it in for the power the job for the
power. Most people don't usually join it for the money and to support a luxurious lifestyle...unless they want to go to the political/administrative route I guess... which is a lot more ass-kissing than butt-kicking.