Disclosed are a system and a method that includes a robotic unit configured to deliver items (e.g., medicine, foodstuff, linens, equipment, etc.) to sites (e.g., rooms, offices, etc.) and / or individuals (e.g., patients, pharmacists, technician, etc.) throughout a facility (e.g., hospital, office building, mailroom, manufacturing facility, etc.). The robotic unit is a mobile unit that operates autonomously to follow predetermined or programmed routes throughout the facility to deliver the items. The system is configured to maintain a chain of custody for the items. In addition, the robotic unit is configured to only allow designated items to be delivered to designated sites and / or to authorized individuals. This can be achieved by the robotic unit having a plurality of containers that are locked within a storage space of the robotic unit, and are only accessible upon successful completion of an authorization process.