Ex assaulted our special needs child

Location: Texas
My ex had his parenting time over the weekend. Our 10 year old came home crying saying her bottom hurt. She has special needs and has the verbal skills of about a 2 year old, but can communicate. I asked what happened and our 7 year old told me their dad had asked her to get out of the floor board of his truck when parked in his driveway. When she didn’t immediately comply, he yanked her by her arm out of the truck and proceeded to drop her onto the concrete on her bottom. He then, according to them, pushed her into the grass while she was crying, drug her inside the house and spanked her. I immediately filed a CPS report. The following morning she was still complaining of pain, but had no marks. I decided to file a police report as well. The officer who responded said it would be marked as felony injury to a child and a detective would be calling me, but it could be several weeks before we hear from them as they are very behind. We took her to the pediatrician to document the pain as well despite lack of marks. I have yet to hear from anyone with CPS or their other parent, which tells me no one has contacted him either. I guess my question is what to expect from here? I have contacted multiple attorneys in our area for advice on moving forward as neither one of my children ever want to return to his home, but it is a 2 week wait across the board to get in for a consultation. Will CPS be able to advise me on how to handle his next court ordered parenting time? My mind is going a million miles an hour. My children have made several verbal abuse outcries over the last 6 months, as well as multiple reports of their other parent spanking only our special needs child, but no marks were ever found upon returning home, and nothing ever as violent as this encounter.