Crime Deterrence
The presence of an armed officer is known to be really good for deterrence of crimes. Just the thought of possible consequences that can lead to even mortal losses stops possible offenders before they could even commit a crime. Committing a crime at a site where armed security officers are present can lead to large consequences which may leave the offender severely injured or even at a chance of losing their lives, hence the presence of an armed security officer is the best crime deterrent.
