Child attacked at school

Looking for some feedback on what I should do next… My 10 year old was attacked by another student who is special needs. He has handlers, and doesn’t speak due to his disability. He grabbed her by the face, shook her around and slammed her head into a wall. She is ok, but was definitely rattled. Apparently this has happened more than once to other students. After the school nurse contacted us to let us know she wanted to be picked up, we wondered why no one else, like the principal or teacher had not contacted us to let us know what had happened.. my wife requested that the principal call her, and when she did, she said that my daughter was only pushed, when her teacher was on site when this went down and gave her the full rundown on what had happened. So basically the principal lied, and proceeded to make my wife feel like an idiot for reaching out for no reason. The special needs child has people who have to be with him at all times, and apparently they were several yards away from him having a conversation and not even paying attention at the time of the altercation.

This situation has got us both extremely upset, and curious why the principal would straight lie about what happened. We want to protect our kids that attend the school, as well as other children this may happen to, because as I mentioned, this is not the first time this student has attacked another kid.. We want to go get a report from the school, but don’t want the principal to know, as we are concerned that she may change what the initial report says to cover her own a**. What would you do?? Thanks in advance