While you as the security guard are the first respondent on emergency security and health issues in your immediate environment of duty, the law is clear. A security guard is not a police officer. Hence, you do not have the right to act like one, you are to only manage and control the situation till the police arrive.
How do you manage some emergency situations?
It is harder and requires more tactics if the suspect is a minor. For cases where you are able to sight the suspect via CCTV, gently walk to them with a team of two or more colleagues and gently escort them to the security room. There you seat them down, give a call to the police, and await their arrival.
Since the first instinct of the suspect is to attempt a run. It doesn’t matter if you are an armed guard, the use of your gun is highly prohibited. Make sure someone makes the police call and once you are able to apply your security training to successfully apprehend the suspect, you are required to calm everyone down, walk them to the security room and await the police arrival.
For every work environment, there should be tactics in place to make sure someone is able to make a police call. Most robbery situations turn bloody because someone always tries to be the hero. Your job is to protect, not be the hero. Do your best to make sure everyone does as the robber(s) instruct, keep it up till the police arrive either during the robbery or after the robbers must have left.
Once a dead body is sighted in your place of primary duty, another guard makes a call to the police while you make sure the people around stay as far away from the scenario as possible. However, you are to make sure all doors leading in and out of the building are sealed. No one comes in, no one leaves till the police arrive.
Hostage situations are by far one of the most dangerous situations in your line of duty. Never try to be a hero but be a protector. When there is a secret means of communication with the police outside, do as trained and let the police direct you to be the hero.
A call to 911 is to be placed first while a member of the team works to apply first aid measures. You are neither a doctor nor are you a nurse. Ask if there are any amongst the people in the environment and if there are none, proceed to prepare the victim for the ambulance.