I think the Op realizes that killing is situational, pointing out rubber bullets as one option.
But since there are so many situations maybe the OP can put herself in this situation.
She is a police officer, she is visiting a school for show & tell day for her 6 yr. old daughter.
A man enters her daughters classroom armed with guns and begins shooting kids. Does she plead with the shooter, take out her nightstick, her taser, or her gun to stop the slaughter of innocent children. Remember police officers are trained to prevent further deaths.