A federal detention hearing is the first hearing you will have if you've been arrested on a federal indictment or on federal charges. At a federal detention hearing, the magistrate judge will determine whether you should be released while your case is going on. The court will look at certain factors like your prior record, whether or not you're a risk of flight, whether or not you're a danger to the community. It's important that you speak to an attorney as soon as possible, because the detention hearing will happen, usually within a day or two of your arrest, so don't wait to go to the detention hearing without a lawyer.