Have read the report and re-watched the video. The police offer said he tasered her groin because she was using her backpack to deflect the taser. She was most clearly not.
He also said there were lots of students blocking the highway. There weren't.
This was outside a High School, so she was an obvious minor.
There were no other students involved, it was a struggle only between him and her. Police Officers are trained to get someone down on the ground for arrest. She is just 14 years old and was not holding any kind of weapon, I am sure he could have arrested her without using that kind of force. If he couldn't then he needs re-training and shouldn't be a police officer. It's not as if he was being threatened by loads of other students.
Despite there being footage missing, you can clearly see that she is fully turned to face him with her hands raised when he tasers her and that whilst he is trying to arrest her, she is pinned against the car. The use of the taser was wholly unnecessary. He deliberately pointed it at her crotch. He's a bastard.
Most charges against her were dropped.
I hope he gets everything he deserves.