How can i file a restraining order ?can i modify custody again because i have concerns about my ex s son molesting our kid

Asked in Redondo Beach, CA - 8 months

My ex filed \got divorce full custody without letting me know ,when iwas going to leave him with our kid then he handed me the divorce paper saying i cant leave with our kid,i have a protective order against him when he was viloent with me and our child,he wanted me to drop that so he will gave me 50\50,i didnt drop the protective order ,after few session ofDV classes he goes to it seems he s back to sense and agreed to file a stipulation and we both have 50\50 custody,we r still in the same house with his son also as we said we will work things out.now i m suspecting our daughter s half brother is molesting her can i file to change custody?at this point i dont think it will work to stay together especially he didnt want to listen to me about my concerns regarding his 15 years old son.