Imagine going to the rest rooms in your company, only to be physically harassed by your co-workers. Trying to get to a stall, you're pushed against a wall. Imagine going to the Human Resources department with complaints about this treatment, and being told that there's not much they can do about it. Now imagine you have to stay in this office building, by law, for twelve years. What he did is indefensible.
Violence is never the answer, and brutal violence resulting in serious injury and death is horrific.
In some, government participated in the deed. In some, government performed the deed. In none, did government prevent the deed. In none, did government punish the deed. Even if Oklahoma were minded to do so, which they apparently are not.