You'll want to make sure that your employee did commit a fireable offense as defined by your company's documents. Carefully review the employment contract, employee handbook, and any relevant company policies to ensure that you are in compliance with the terms and conditions of termination. Ensure that your policy outlines a clear discipline structure and that you follow it as it is laid out. For example, if your company policy states that the first time an employee is late, then they get a warning, firing them the first time they show up late to work can result in legal action. You'll want to be clear with the employee as to why you're firing them and document the entire process. This includes a signature of your company's handbook at the beginning of their employment, outlining that they've agreed to your company's terms and conditions of employment.