Can Thieves Detect Laptops in Cars?

I recently received a question from a reader asking how thieves were apparently able to detect laptops out of view in locked cars, say either covered up or in the trunk (or “boot”, depending on where you live).

This is a topic that’s seen batted around for some time and has attained the status of urban myth, with its share of believers and disbelievers and little in the way of hard facts or proof.

It’s a question I started to look into some time back, but for one reason or another I got sidetracked and never followed through to a conclusion.

Having the question raised again prompts me to present what little I know and request input from anyone who may have definite knowledge, particularly from any technicians who have experience with the types of devices I’ll mention hearing of.

I’ll start with what I consider to be the most unlikely method of laptop detection.

Inductive Amplifiers

Now this is just something I’ve pieced together from bits and pieces here and there, so in mentioning it all I’m trying to do is open the discussion. I’m definitely not suggesting this is possible or practical — because I simply don’t know — but frankly I doubt it.

Proponents of this “myth” claim that it is possible to detect the presence of a laptop computer using a device called an inductive amplifier.

There have been quite a few unsupported and unsubstantiated reports that police in Selangor, Malaysia caught thieves red-handed with one version of an inductive amplifier, called a Model 200EP Tone Probe, that particular device being manufactured by Tempo-Textron, but there are of course many others. [Note: I found the Tempo-Textron site to be out of service a lot. Sorry, but nothing I can do about it.]

Personally I’m more inclined to think that any thief in possession of an inductive amplifier would be using it to disable car alarms.

Battery Detectors

Another fairly common suggestion is that the presence of a laptop can be detected by use of a so-called “battery detector”. Various types of battery detectors do exist, but to my knowledge their effective range is very small, and there would be myriad problems using such a device to detect a laptop in a car. For one thing I would expect that the metal enclosure of a car boot would provide a very effective barrier, not to mention all the other power sources that are constantly active in a vehicle.

As to the electrical properties of a laptop, there is ALWAYS some power present, whether the laptop is shut down or not, even if you remove the main battery. On the computer’s motherboard is a small battery much like that which runs your electronic watch. For historical reasons it is generally referred to as a CMOS battery. At the very least this battery maintains the real time clock, and it may maintain other settings as well. I believe voltages range from 3 volts to 4.5 volts, depending on make/model/brand/etc. There may even be more than one such board-mounted power source.

But detecting a laptop in a motor vehicle with a battery detector? I’m sceptical.

Bluetooth Scanning

The more obvious danger is leaving your laptop on or in sleep mode, such that its Bluetooth capabilities (if any) are active. Bluetooth scanning will reveal not only the presence of a laptop or high-end phone, but also its make/model. And such identification opens up the possibility of “steal to order”, allowing high-end devices to be specifically targeted. There’s plenty of information available on Bluetooth detection so I won’t belabor the point further here. Anyone wishing to research this further could try some of these keywords:

• Bluetooth Scanning
• BlueBugging
• BlueJacking
• BlueSnarfing

I don’t think rehashing unsupported myths and suppositions serves any purpose, but if you have any definitive information on how laptops and/or high end mobile phones might be detected inside a locked car I’d certainly like to hear about it. Please use the comments box below…