The Acknowledgment of Paternity Affidavit may not be used in your situation, but you can still establish a legal father for your child. Here's how: If the mother lives in Ohio, please contact the Child Support Enforcement Agency (CSEA) in the mother's county of residence. If the mother lives outside of Ohio, you may contact the CSEA in the father's county of residence. Click here to go to the Office Locator Map and find the appropriate CSEA office for your case.