It's honestly as cliche as they come. He joined the force to clean the crime off the streets; but his impassioned zeal, propensity for violence and fatalities, and overall disregard for protocol would get him into trouble with his superiors, even if he did do his job extraordinarily well.
He doesn't exactly pick fights, rather he hasn't a modicum of "good cop" in him, which tends to provoke suspects and perpetrators into escalating to violence, and then he responds appropriately. He's not a bad guy, just fiercely dedicated to his purpose. If they park it like it's hot, he won't turn up the heat himself. Don't run away, either. He can run, but his bullets fly faster.
Feeling restrained, he turned in his badge and gun, picked up a bigger gun, and became a PI, hiring himself out to people in need, and throwing himself straight into hell.
I designed him visually and characteristically to be Sprint's nemesis and contrast, but the two of them fall on the same spot on an alignment grid and should learn a lot from each other.