Ok . I ' m going to try to make this as short as I can . LolI am a 911 Paramedic , and have taken a class called TCCC which is basically tactical medicine . A taser , when used properly , and when it functions properly , achieves what we call TNI Total Neuromuscular Incapacitation . You can not overcome this . It blocks the brains electrical signals to muscles by introducing outer electrical stimuli . HOWEVER . As great of a job as Taser does in manufacturing their products , they aren ' t perfect . I don ' t know true statistics , but they fail to achieve this effect commonly . Probably about a third of the time . Meaning , one of the barbs came out of the skin , or got stuck in a shirt , or whatever may cause it to lose contact and conduction . Furthermore , in this case , they continued to issue the command of Drop the knife after the taser was deployed . If TNI WAS achieved , Lucas was no longer able to drop the knife , even if he wanted to . They have to wait for the Taser to finish it ' s cycle , 5 seconds , before he is able to control his muscles again , and hopefully loosen his grip on the knife . All in all , they did everything right . They escalated the situation properly , from negotiation , to LessThanLethal , and finally lethal force . Terrible situation , that these officers will have to live with for the rest of their lives . But the proper decision making sequence , showing proper education and training on the part of all the departments involved . tldr You ' re both right . There are so many variables that we don ' t know and will never know . Did the Taser work ? Was he trying to let go of the knife ? Did he really know they were cops ? No way to tell .