If you have an alarm system, check it out regularly to see whether it's in proper working order. Keep close tabs on keys. A poor key control system leaves you vulnerable from both inside and outside your business. Re-key locks when in doubt. Install adequate lighting both inside and outside.
Illuminated property is less appealing.
All of the steps you take to prevent burglary will help you cut down the risk of robbery, as well. Don't underestimate the value of good lighting, good visibility, sturdy locks, key control and a working alarm system and though background checks on employees. These measures are also vital in stopping holdups. Suspects will soon learn it. Discuss only business with the tellers.