A Child Custody Affidavit is a legal document used in family law cases to provide information about the child's best interests and the custodial arrangements. Everything you need to write a declaration letter to the judge in your custody case: an example, a downloadable template, an outline and tips.To make a sworn statement, you ordinarily present yourself first and after that swear that you will come clean in the testimony. Use the form with the boxes to guide you through filling out the blank form. This purpose of this packet is to provide you with the information and documents you may need to start or respond to child custody actions. You write a DECLARATION, under PENALTY OF PERJURY and state in the beginning: I JANE SMITH, DECLARE: 1. Affidavit of Service - Personal Service, PDF ; Certificate of Service, PDF ; Complaint for Custody, PDF ; Complaint for Custody - Two Defendants, PDF. The person who delivers it should fill out the affidavit of service and you should bring it to the hearing with you. What happens after I file? So you can read the instructions for each form as you fill out that form.