the taser is a weapon which is designed to incapacitate, but not to kill.
if you think otherwise, you are welcome to argue with a taser engineer, dictionary, or yourself in the mirror.
And while I have you incapacitated with the taser I can take your duty weapon and kill you.
Would you want to walk into, say, the bad section of Detroit and let some teens tase you? Or might that wind up being a potentially deadly situation?
Has anyone ever died from having a tazer used on them? If so, then a tazer can be a deadly weapon.
A screwdriver is a tool which is designed to put in screws. If turn it against you, is it a deadly weapon? I mean, according to your argument I can stab you repeatedly with a screwdriver, and because it was engineered as a tool for screws you cannot die. Or, for that matter, be in imminent jeopardy of death or serious bodily injury, which is the standard for use of deadly force.
Is this how your mind works?