How do you get full SOLE custody

My sons dad is in jail and was very abusive towards me and my son , I want to know how I can go about getting full sole custody where his dad could never see him, for shits and giggles I have video evidence of him hitting my son and he’s screaming I’m the background.. I just don’t want acs to know, they will take my son . I just don’t want cps in my business and I want to get granted full custody without him trying to get any parental rights, my son is one 1 years old! I want his rights relinquished where he can never see him.. does anyone know how I can go about this process? I have a oop for 5 years as well but my son isn’t included.I know family court can help but how can his rights as a parents be relinquished