That's great that you think that LEOs are Supermen, but we're not. We're normal humans just like you are.
You have two LEOs attempting to subdue an insane person with a knife. The tazer (UFC 1,2,3 and 4 exhausted) there are not only members of the public, but two LEOs facing possible death. What do you suggest they do?
Shooting to kill ain’t how you “subdue” a person. It’s how you “KILL” a person.
I think law enforcement either needs to look in the dictionary, or banish outright stupidity on display in the force.
Subdue - Verb
Overcome or bring under control (a feeling or person).