It seems to me that I see stories about police murders every day, from one to six a day.
That brings up an interesting thought. Someone should start tracking such quick-use-of-lethal-force events, similar to how DaveLoneRanger and others used to track self defense acts that involved using a firearm.
As you say, there are a lot of them.
Part of the issue may be that due to liability, cops no longer equip and train with 1 yard long riot batons. You could keep some distance with an unarmed violent subject using one, and cops might not feel the need to immediately resort to gunfire.