Hey. It's not the cop's fault.
She was physically harming HER OWN MOTHER to the point where the mom had to call the police. She tried to assault the police officer, and he just did what he thought would work. She has a history of epilepsy, but that doesn't call for charging a police officer. Even if he managed to subdue her and take her in, she would have been charged with domestic violence and assaulting a police officer.
Also: DON'T TASE ME, BRO!