Bill Monroe was a Weyland-Yutani Corporation employee and a supervisor in charge of the mine at the colony of Bowen's Landing. He was working at the colony when a group of miners encountered a lone Xenomorph in the mine where they worked.
Upon learning of the Xenomorph's existence, Monroe was locked out of the facility control room by his synthetic colleague, Hanks, who was trying to preserve the creature so that it could be recovered by the company for study. It is unknown if he survived the Xenomorph incident.