Be safe in your home


There maybe some things to cheer about in the [latest crime statistics][], but it's not all good news, sadly.

Toby Kurien articles alarm armed response crime statistics house robbery motion sensor security

There maybe some things to cheer about in the latest crime statistics, but it's not all good news, sadly.

While most of the statistics show a slight downward trend, a few worrying stats remain. These are mainly the ATM bombings, house robberies, car hijacking, and business robberies. Residential robbery is of particular interest. To quote the article from

According to the report, residential robberies are usually committed between 9pm and 3am (55 percent) by "small groups of unemployed youths" who, in almost 90 percent of cases, surprise their victims inside their homes.

This surprises me. How is it that so often, the victims literally wake up to a gun against their heads?

A few years ago, my house was burgled. Thankfully, it happened at a time when nobody was home. However, the incident got me thinking carefully about how the security at home was implemented. A year before, when I moved in, I had installed an electric fence and a house alarm system that was linked to a security company. None of my neighbours had an electric fence. I figured that if my house was harder to break into than my neighbours, I would be ok.

The problem with the system, however, was that it was focussed on detecting a break-in. It worked, mind you. After the gate was removed from it's rails and opened, the security gate on the front door was ripped open with a crowbar, and then the front door soon succumbed to the relentless tool-wielding thieves. Aha! The ever-alert security system sprang into action! It immediately responded to the "open" front door by beeping for 30 seconds. This, you see, gives the home owners a chance to run into the bedroom and enter the code to disarm the alarm system. However, since these weren't the home owners, it gave them plenty of time to spot the audio visual equipment and start relieving the house of their burden. The alarm system was not to be defeated though. Oh no, having not received it's disarming code, it promptly set the alarm off, thus alerting the armed response company. They, in turn, called the house to verify the validity of the alarm. After a few tries, they concluded that this may infact be an actual robbery in progress, so they called one of their patrol cars to go have a look-see. By the time that happened, the enriched burglars were probably having a shot of scotch at their local watering hole.

This is the reality of many of the house alarm systems that get installed these days. They have a special offer, where you sign up for a security company contract and in return they install a free alarm system with something like 2 sensors and a keypad. While this may lower your insurance premium somewhat, it does nothing for you and your family's personal safety. All it does, is make it easier for the guy pointing the gun at your head to wake you up.

I decided that I needed an alarm system that isn't focussed only on detecting break-ins, but rather one that is focussed on alerting me to any suspicious activity around my house, while I am in the house. Being the crafty engineer that I am, I immediately began designing a circuit that would hook up to the front gate, so that if the gate was opened forcefully, it would immediately set off the panic alarm. I built the circuit and it worked. I immediately felt safer, because I knew that even if I had not activated the alarm, any messing about with my front gate would set off the panic alarm, which in theory would yield a better response from the security company. However, several thunderstorms and two blown circuits later, I gave up. I decided to extend the idea using off-the-shelf parts.

The security system I designed is based on the simple idea that I want to be alerted of any suspicious activity in or around my property before any break-in happens. I don't need to know once my house has been broken into - that's already too late. This is very much what a dog would accomplish, except that I don't have a dog, and dogs also tend to bark too often to be taken seriously all the time. I went to some local security shops (Yale Security Point and Communica) to find out what sensors they sell, how much they cost, and how they work. Since I'm technically minded, I decided to design the security system myself, although any security consultant would be able to do the same. Firstly, I had to do away with those ridiculous 30 second timeouts on arming and disarming. This meant getting secure remote controls to activate/deactivate the alarm. I then used outside motion detectors at various points around the house, especially all the entrances and windows. I drew out a map of my house and property and then mapped out the "footprints" of the sensors (from their specifications sheets) to ensure adequate coverage. This would ensure that if anyone scaled the perimeter fence, they would set off chimes or the alarm if they so much as approach any part of the house. I took it once step further - if anyone even walks across my driveway outside my property, that will set off a loud chime inside the house alerting me to the fact. This way, I would know if anyone was tampering with my gate while I am in the house. It takes a bit of discipline to get out of bed at 2am and check what's happening in your driveway when the chimes go off, but the beauty of the system is that there are no false alarms. If I hear a chime, I give it due respect.

Does this make me less inclined to become a crime statistic? I think it helps. There's no guaranteed way to thwart crime, but I sure as hell feel a lot safer. It helps that I have a house on a cul-de-sac and a yard that's easily covered by motion sensors. If I was living in a second-floor apartment, things might be different, but my approach would be the same - add beams or motion sensors with chimes and cctv cameras so that I know what's going on around me.

How much does this all cost? Since I designed the system myself and sourced parts from the suppliers of the security shops, I got a good deal - roughly about R7000. The outside motion sensors don't come cheap - they are about R2000 each for the good ones (VX40). It's a worthwhile investment, in my opinion.

My next step is to know about a crime being planned, while it is being planned. While I'm at work, there may be people (for example the building contractors next door) checking out my house. By linking my driveway motion sensor to a night-vision camera, I can get a picture of whoever ventures near my gate anytime, day or night. If I then have this MMS'd to my cellphone, it will be pretty much like I'm sitting at my front door 24 hours a day, watching what's going on!