Visual Deterrents
One of the primary goals of criminals, is to avoid any chance of getting caught. For most criminals, to be in and out after committing a crime and "getting away with it" is the most ideal scenario for them. This is part of the reason that things such as: security gates, access control (doormen, metal detectors, locks), CCTV cameras, tall metal fences, warning signs, et cetera.
However, that being said, there may not be a guarantee that they will not commit a crime. It may, however, ensure that the more difficult crime to commit and less chance to "get away" with it, the much less likely they will commit it on this property.
This is why security gates have such a strong advantage over other tools such as window film. While both make it more difficult to break through glass and enter a property, only physical gates let criminals know that there is security installed. With window film, a criminal could look at a property, assume that it is unprotected and then attempt a break-in. Whether the break-in is successful or not, this will cause damage to your property or unwanted attention. Such damage can be costly and even require you to temporarily close your business while repairs are made. Obviously, this would hurt your company and your bottom line.
On the other hand, a criminal will clearly see when security gates are installed. They will understand that these gates will make it significantly more difficult to break into a property and, thus, they are much more likely to move on to another property where the chances of a successful break-in are likely.
Physical Security
Having the physical presence of Security Guards not only deterrs crimes but also prevents them and intervenes with them. Especially, seeing a fully equipped Guard with a Vest, and belt accessories such as handcuffs or batons; can be to be too much for any criminal to handle. A well trained and well equipped Security Guard, will increase your chances of crime prevention/intervention by 100%.
This form of detterent also gives an impression and duty of authority. When criminals are in the presence of authority, they tend to recognize the risks of being caught increasing significantly. Evenso, having additional security features such as cameras, access control, gates and fences, and proactive assistance from staff - could make all the difference.
Physical Security is the most commonly form of Security contracted services. Most commerical / industrial related environments with a high volume of customers, workers, 3rd party workers, etc. - are very likely to have several different security features implemented, with Security Guards being the top selection.
Signs, Gates & Fences
Not only is having sign posted rules around your property a legal requirement; it is helpful in advising the general public as well as warning criminals and deterring violations of your property rules / official law.
As for gates and fences, there are a number of ways these can be most effective. Gates are most commonly found on the very edge of the perimeter of the property, but is also found indoors wherein sections of the building may be cordoned off in case of emergency or an overnight lockup. Gates aside from guards, are the second most effective deterrent. If you have an 10' high thick steel gate with barbed wire ontop, there is a very good reason not to attempt trespassing, as this may injur the potential perpetrator(s). Fences are used in squence with gates, to ensure a fully secured area. The fences are meant to act as an impassible barrier and potential perpetrators are forced to find another way in.