The Illinois Petition for Writ of Habeas Corpus -- Person In State Custody is a legal document that is used to challenge the legality of a person’s imprisonment or incarceration in the state of Illinois. It is a petition to the court to release the person from custody and to issue a writ of habeas corpus, which is an order for the jail or prison to bring the person before the court and to explain why they are being held. The petitioner must prove that the person is being held unlawfully, that their rights are being denied, or that they are being held in conditions that are outside the scope of what is permissible in the state. There are two types of Illinois Petition for Writ of Habeas Corpus -- Person In State Custody: the original petition and the amended petition. The original petition is the initial filing that is made with the court when the petitioner believes their rights are being violated by the imprisonment or incarceration. The amended petition is used when the petitioner has found new evidence or changed circumstances that they believe would invalidate the original petition.