text: For police, tasers are a compliance tool, they are not appropriate as a response to an immediate lethal threat situation unless there is a physical barrier and a weapon that cannot cross the barrier.  You might Tase a guy with a knife on the other side of a reasonably high fence who refused to drop the weapon, for instance. Tasers fail, when it is a gun at close range and a non-compliant suspect, they are not the tool for the job.