Men who served in combat in WWII, Korea, and Viet Nam.
None that I knew behaved in the manner of the individual that shot the young man.
The more I go over what has been reported, I now believe that this man decided sometime before that he was going to kill the suspect when he caught him.
That he did not kill the man had more to do with the Grace of God than his lack of trying.
Also agreed that most soldiers who enter law enforcement do the job just fine. Unfortunately, some end up confusing their "kill people and break things" training with the "bring bad guys to justice" imperative - and the consequences should cause us to reconsider such crossovers.
Through all of history, there has been the problem of what to do with soldiers not in or preparing for combat. Many can transition fine, but those who don't are a problem.