What can I do if my ex husband stole my computer and twisting my story?

My ex husband and I are very bitter with each other. He left me and took everything including primary custody of our kids. He and his girlfriend have been provoking me in fights. I stumbled into information and copied it all for my records that they were intentionally doing things so I would fight with them. And they could wait for the document then they call the cops or CPS call me unfit and other to have my rights taken away. I left the other night and he found out that I knew about their plan to take them and he happens to still be on my lease where I live. But he took our child's key came in and stole all my kindles and my laptop. It was the only thing I had worth value that I paid for after our divorce. How can I prove he did this? How can I get it back without being arrested myself? He's twisting the story now to say that he didn't know I was gone but he replied to a text after I told him I was gone. And now says that I made up the text and stole my own stuff and blamed him. He is trying to take the kids and the cops won't do anything. Help please.