It is negligence, but she also wasn't trained on it and it was a new weapon for her. On the Department too, who should be sued.
I don't know how they wear them there, but every police officer I've seen has their TASER worn weakside, with the pistol grip forward, so you actually reach across your body to grab it. Maybe they don't do that there, I don't know, but that is something that Department probably needs to look into.
Still, her actions led to the death. It is on her to be proficient with everything she uses. It is on her department too, but she is frontline on it. I think it is negligent homicide, or whatever term they use for it there.
Ceterum censeo Carthaginem esse delendam