Since police also killed a man with mental problems in Texas in a similar way, I link a lot of it to the police Training. Police do not normally go out to murder people. They may if there are other factors involved.

I see the police training in this area as a huge problem. If they are on angel dust and other drugs that make them fight even when they are over numb to any force of say lot of police then something needs to be added to their inventory and it needs to be able to safely bring them down without killing them. You can use a net and I mean a net, hard to fight out of a net. Think fish net from the sea. They may trip and do some damage only their lives may be saved.