What type of custody case do we have?

Thank you for your question.  I have reviewed the facts presented and do not feel that your question can be answered in this forum.  There are too many unanswered questions.  As a preliminary matter, your husband should speak with his children to ascertain whether they have in any way been compromised.   Under what circumstances were the children in the presence of the boyfriend?  Were they ever left alone with him? Did the boyfriend live in the home at the time of the offense?  Does he live in the home now? Were the children in question in the home during the time the sexual assault took place?  What is the boyfriend's current level of exposure to the children? Has your husband had a calm and civil conversation with the biological mother concerning this matter?  If so, did he feel that she was forthright in sharing information regarding any risk the alleged perpetrator posed to the safety of your children? Did CPS put into place a plan designed to protect all "at risk" children in the home?"  Has the CPS investigation been concluded? If so, was it "founded" or "unfounded?" Did CPS file an abuse and neglect petition? If so, is there a pending hearing?  If not, why? What if any recommendation were made by CPS?  Lawyer.com offers general information and not legal advice.  Legal advice is based on detailed facts in a particular case. It is recommended that your husband schedule a consultation with a family lawyer in your area to discuss this matter in greater details.  Most lawyers charge by the hour for office meetings.  Therefore, you need to verify the cost in advance before scheduling a meeting.  Best of luck~