How can I find out if I have a case against a police officer for harassment and threatening?

After a visit with my ex my 10-year-old daughter came down with a fever and became very sick . By morning she threw up blood and I needed to bring her to the ER. I informed my ex but he still showed up with two police officers to do a wellness check on my daughter. He was allowed to go into my bedroom where my daughter was to speak to her . While at the hospital he came in and threatened us and security how to remove him. After returning from the hospital with my very sick child he came back with one of the police officers that did the wellness check and now this officer claimed that my daughter had stolen a cell phone from my ex and that if I didn't return it he would have me arrested. He stood in my doorway and preventing me from closing it while he screamed and threatened me with a Warrants for my arrest for all sorts of things while my little girl stood and screamed in fear. I asked him multiple times to stop screaming at me but he continued for at least 30 minutes.