There seems to be some room for innovation here. The police are throwing these things blind. Evidence? Well, I refuse to believe anyone, no matter how debased, would intentionally throw a flashbang into a baby's crib. What's needed is a flashbang that either won't go off if in close proximity to a living being (e.g. perhaps add an IR sensor) or a flashbang that is triggered remotely, so it can be thrown, spotted, and…
I can. In the extended circle of acquintances, two of the cops are the worst abusers of their families, children & wives, the are the most racists and full of hatred. One would enjoy showing others how he would spin his son by his hand while simultaneously kicking him in the back with his foot (granted this is not a US policeman, not that a US policemen are somehow qualitatively more noble).
I think there is link between saddism (enjoyment of inflicticting pain) and choosing to be that kind of a profession (just like there might be a link between wanting to help people and choosing to do it).