1. Introduction: Briefly explain the purpose of the letter and the investigation. In your police officer cover letter, it's important that you emphasize education, work experience, a clean background, and community service.In this article, we discuss some key elements to include in a police cover letter and tips for writing one. You should fill out an Acknowledgment of Demand Form and get a copy. Interested in becoming a police officer? Do you think you have what it takes to be a member of the Decatur Police Department? Please be aware that forms will be displayed in a NEW browser window. A Letter of Clearance is a letter that certifies whether a person has been convicted of a criminal offense (excluding traffic or minor regulatory ordinances). How much does it cost for a Service of Process? If you fill out a form on a webpage, you will lose your progress.