Trial court properly instructed jury that a jail officer must give informed consent in order for an ex-convict’s entry upon jail grounds to be authorized. Appellant used his revoked private investigator’s license to enter a county jail to interview an inmate. Although a sheriff’s deputy gave him permission to enter the jail, appellant had failed to inform the deputy that he was an ex-convict. He was convicted of violating Penal Code section 4571, which prohibits ex-convicts from entering prison grounds without the consent of the warden or other officer in charge. At trial, the court had instructed the jury that, in order to convict appellant of a violation of section 4571, it had to find that defendant “did not have the informed consent of the Warden or other officer in charge of the jail facility” when he entered the grounds. On appeal, appellant argued that the trial court erred by instructing the jury that “informed consent” was required. Held: Affirmed. Section 4571 does not specify the type of consent required and no published cases have defined the term “consent” for purposes of the statute. Applying rules of statutory construction, the appellate court concluded that section 4571 requires informed consent, as the trial court instructed. The court also relied on an Attorney General’s Opinion, which provides that section 4571 requires that the officer must have knowledge of the prior conviction in order to consent to an entry by an ex-convict. It would be impossible for the warden or other officer in charge to consider the ex-convict’s criminal history and make an individualized determination regarding entry without knowledge of the ex-convict’s prior conviction. The official processing visitors does not have a duty to access the criminal history of every person seeking admission; the burden is on the former prisoner to inform the official of his status.