The Writ of Habeas Corpus is the legal system's last line of defense against unlawful incarceration. On December 5, 2007, Richards filed a Petition for Writ of Habeas.How Do I Fill Out the Form? There is an official form (Judicial Council Form HC-001) for filing a state petition for writ of habeas corpus. Writ of Habeas Corpus Petitions. Habeas corpus refers to the principle of freedom from unlawful detention. It offers collateral rather than direct review and is discretionary with the court. The habeas petition is for situations when a legal error occurred, as we say, outside the "four corners" of the court file. " (The Court will fill in the date if approved for signature).