Security

Background

While going to college, I worked for a small alarm company. I learned a lot not only about installing alarms, but about the selling, the maintaining and the effectiveness of security systems.

For example, the best time to sell an alarm system is right after somebody is robbed. After such a sale, it is imperative to start installation so the customer doesn't reconsider and change their mind. One time we were working installing a master antenna system and intercoms for a large garden apartment development. The owner got a call from a homeowner who had just been robbed, and sold her a really expensive (every door and window) system. He also promised it would be installed "right away". The next day we installed the panel in the basement and a siren/strobe box on the side of the house. He then told the customer we had to pick up some parts and would be right back. We didn't come back for 2 weeks.

Some other observations:

• Burglars almost never crawl through windows. They almost always force doors and just walk in.
• Alarms are no substitution for gates. We got lots of repair calls after smash and grab thefts, or even just burglars trying to break in to see if the alarm really works.
• A simple alarm that the owner can use all the time (i.e. home or away) will be the most effective and reliable. We used to get lots of panicked calls from homeowners who rarely used their alarms and were leaving for vacation and alarm wouldn't arm.
• Monitoring works - at least the owner gets a call that the alarm went off. In one instance the owner went to the store and found his store flooding from a broken pipe. In another there was a fire in an adjacent building and the firemen had broken into the store to check for flame. They were about to drive away with the store wide open when the owner showed up.
• False alarms really diminish the effectiveness of a security system. For commercial alarms we always put up bell boxes because sirens are always ignored due to the prevalence of car alarm sirens.

Threat Analysis

This is the key for security system design. Robbers will break through walls to get into jewelry store, but won't bother for a hardware store.

Response

If your alarm or security system is activated, what happens? A blaring siren might be good enough to protect a detached garage, but not an office in an business park at night.

Defense in Depth

Alarms should be installed with multiple zones, and even with complete perimeter protection, some space protection should be used. The intent is that the alarm can't be disabled by cutting a single wire and that if a zone is disabled, the alarm will still protect the premises. (In the old days of foil tape, burglars would enter a store during normal hours and with a ring or razor cut the foil to disable the alarm. They would then come and rob the store that night.)

Outdoor sensor technology can be used to protect driveways and parking lots. Rather than alarms, vehicle detectors, motion sensor/beam combinations can trigger lights or strobes for a few minutes when the protected areas are entered while the main system is armed..

False Alarms

These should be avoided at all costs. Dual tech motion sensors, or even multiple parallel sensors can be a good idea. Beams are an alternative to motion sensors for areas with vermin. For complex systems, it would be a good idea to run the system the first few nights without monitoring turned on. Good clean installation practices, with multiple zones helps to cut down on and help troubleshoot false alarms.

Video

For video to be effective, it must either be monitored constantly (not realy practical) or recorded. What it really helps prevent is losses to employee theft. Motion sensing video used to trigger a lot of false alarms, but is now better. However, it is no substitute for perimeter protection.