As a night shift security officer, your job is to ensure the safety of a building or business by helping monitor it overnight. In this role, you may watch video from security cameras, respond to alerts, patrol the area, or perform other tasks as necessary based on the security systems in place. Most night shift security officer positions have specific guidelines for what to do in different situations, so the ability to memorize security protocols is an essential aspect of this job. Other details of this position vary by company. For example, some employers may only want you to monitor security footage and decide whether or not to call for the police while other employers may ask you to use various tools and equipment to stop intruders.