One of the most important roles of the Judicial Branch of the Federal Government is to promote justice in the United States of America. In order to do this the Judicial interprets the law passed by the Legislative Branch and determines the viability of the law in relation to the Constitution and the Amendments. There are multiple ways that a statute passed can be in contrast with the Constitution and the Amendments. One of the most common is that the statute does not pass the Void for Vagueness Doctrine. The legal concept of void for vagueness is very important to ensuring fair and just criminal system. Void for vagueness refers to a statute that while defines a crime, it is impossible for a person of ordinary intelligence to tell what the crime is from that statute. This makes that statute void because it would be unconstitutional under the 5th amendment which guarantees due process. A law that is to vague cannot be followed by a citizen and could turn a normal law abiding citizen unwillingly into a criminal. There must be a clear standard for what a crime is and what a crime is not for a democracy to survive.
An example of a law that would be struck down for void for vagueness would be a statute that says that any known gang member cannot loiter in a public place in groups of two or more. This seems, on the surface, to be a law that would be useful to Law Enforcement to disrupt gang activity in cities. One of the problems with a law like this is that it violates the void for vagueness doctrine by not defining what makes a person a gang member.