Peter Levine has written about the fight, flight or freeze response and how "as they go in, so they come out". If you were in fight mode during trauma then had to freeze for survival, that fight response is held in your cells waiting to emerge when you come out of freeze. He says, "The impulse to attack in frantic rage, or to attempt a frantic escape, is biologically appropriate. When captured prey come out of immobility, their survival may depend on violent aggression if the predator is still present."
Unfortunately, because we curb our animal instinct to discharge fight/anger energy when we unfreeze, we're still holding it in and it will try to emerge - then we express it or manage to suppress it again. (Same if it's flight/fear energy.)
I once experienced literal murderous rage when someone in the street tried to grope me. I went insane with anger and didn't know what I was doing other than feeling an all-consuming drive to kill him. Luckily he managed to run away, because I'm certain I would actually have done it otherwise. I was literally out of my mind and had that intense adrenaline-fired strength that comes in emergencies.
I understand now it was because of past trauma, and the description of the unfreezing fight response is exactly what was happening. At the time I had no idea about that. By normal standards, my response was completely out of proportion and it scares me how easily I could have been convicted of murder. At the same time, I have to say it was the purest emotion I've ever felt.
Now I still have bouts of rage and violence, and they're bad but they're controllable. That's good in the sense that I hopefully won't end up in jail, but I'm aware of how I'm still suppressing it so it isn't going away.