https://www.washingtonpost.com/news/morning-mix/wp/2014/08/1...
(Of course we can discuss if most of the uses of tear gas are wrong, but lets for a moment think that we have a moment were we need to chase away a crowd of evil persons riotong and threatening to kill perfectly innocent children.)
But, we have de-escalation tactics, riot shields, smoke canisters, and literally guns.
If an officer wouldn't fire a gun, I think he shouldn't use tear gas.
I'm willing to grant the police the power to appropriately use force and give them the broadest spectrum of options to match to the need. That's not dependent on them showing for a whole year with no force that they've thought about what they did wrong so far.