Specific laws aimed at the confinement of mentally disabled sexually violent persons have existed for years. Originally, these laws aimed to rehabilitate a person within a mental hospital and help him with his disorders, aiming to help him enter back into society. However, throughout the years, the laws morphed into ways to keep convicted criminals from society after their prison sentence ended for fear of potential future crimes. In Illinois, the courts find a man falls within the sexually violent persons law when he remains too dangerous to be released after his criminal confinement. A person must have a “mental disorder” to fall under this law, and questions remain on how these disorders are established. In Illinois, a psychologist often makes a “mental disorder diagnosis.” This Comment argues the state should have the psychologist qualified as an expert using a Frye hearing before the expert can classify the person with a “mental disorder” within the sexually violent persons law. This way, the person is classified using a legal classification, not just the prevailing psychological definition of the day.