ALARM SYSTEMS, TIME-DELAY SAFES, and cameras are used extensively in security, but their effectiveness in reducing robbery rates has not been well documented. Only a few studies have systematically assessed security system effectiveness, producing results that do not always square with the frequency with which such equipment is used. The effectiveness of alarm systems and cameras has not been demonstrated when standard research procedures are used to assess their impact.
One study used 181 interviews with convicted armed robbers.' It found that security equipment was not particularly important to robbers when they selected a target. Of I I factors rated for importance in determining the attractiveness of a robbery target, a camera, an alarm, and a video recorder were ninth, 10th, and 11th on the list, respectively. As expected, the amount of money was the most important factor to the robbers.
A second study, conducted for Southland Corporation, found that robberies decreased in two experimental sites after cameras and silent alarms were installed, but the decrease was not large enough to be statistically significant. Afterwards, security managers indicated they did not attribute the decrease in robberies to the cameras and alarms. Store clerks, however, liked the equipment primarily because it increased their feelings of safety and security.
From the point of view of the security practitioner faced with robbery prevention, these studies shed little light on ways to deter robberies. Actually, they are disturbing if installing security equipment gives employees a false sense of security.'
One difficulty with the published material is that it runs counter to the experience of many security professionals. The authors' experiences in restaurant chains throughout the country indicate security equipment is effective in reducing the incidence of robbery. Anecdotal experience, however, is not the same as well-researched, documented proof. The discrepancy between the published research and experience gave the impetus to assess the effectiveness of in-store security systems at Taco Bell restaurants.
THE SECURITY EQUIPMENT INSTALLED AT Taco Bell restaurants consisted of the following:
* Alarm system. An alarm system with hold-up buttons was located at each cash register, in the manager's office, inside the walkin cooler, in the stockroom, and near the drive-through window. The alarm system also included a passive infrared motion detector for burglary detection.
* 35 mm camera. Such a camera was in plain view of the public and could be activated by an alarm button. The alarm system also included a passive infrared motion detector for burglary detection.
* A safe. Safes had an inner compartment that operated on a 10-minute time delay. Managers were instructed to place the majority of the funds in the time-delay section of the safe after 6:00 pm and to open this section only after the restaurant was closed to count the deposit. Field security staff could not measure how often the managers used the time-delay section but believed it was not used routinely by all managers. In this study, neither the motion detector of the alarm system nor the time-delay safe would substantially affect the rate of robbery.
* Signs. Signs were posted in restaurants advising the public that the restaurant was equipped with an alarm system and a time-delay safe.
* Robbery prevention kits and training. All restaurants, whether equipped with security equipment or not, were given robbery prevention kits and training in robbery prevention.
To assess the effectiveness of this security equipment and training, the second author was given access to Taco Bell robbery files. These files contained robbery information on company-owned restaurants since 1984.
Fifty-one restaurants' robbery rates from 1984 to 1987 were analyzed. These restaurants were included on the basis of having a security system installed about halfway through this period. …