Phone call tracing setup

The machines are mostly so the police can listen live to the phone call. As far as tracing it doesn't really require equipment on the police end. Telephone providers know where the call is coming from and where it's going and will provide that information to law enforcement unless the criminals are very sophisticated. This information can be gained even weeks after the actual call (probably years).

The only ways around are to use VOIP and spoof your IP address or using a 'burn' phone.

Yep, pretty much. If the criminals are that stupid. If they're above your average level of criminal intelligence they'll at least use a burn phone. This can still be traced to an approximate area and a phone number, but if it was purchased with cash they won't be able to find who owns the phone and if the criminals are smart they'll dump the phone or give it away to some homeless guy when they're done with it.

You have two separate things going on here. One is tracing the call and the other is negotiating with the kidnapper.

As Drachen says, tracing a phone call is relatively simple. Landlines require some fancy skills to foil tracing. Burn phones need to be used once and tossed, as they have a GPS unit in them. (If you're smart, when you toss them, you toss them on a truck and let it travel.) GPS tracking is in a matter of seconds and accurate within less than a half mile. But a short call still works.

There are ways to work around this, but it's complicated.

Negotiating is a big part of dealing with kidnappers. Less so in the US and the UK, but even to some extent here. You want to negotiate proof of life, time, and anything else you can think of. You want to slow down the process and make the kidnappers communicate to the maximum.

Best of luck,

Jim Clark-Dawe

I work in the IT department for a major phone operator. I'm a manager nowadays, but I still know plenty of the practical stuff.

To add to what's been said already. You can even use the phones to triangulate the position of the person calling. The accuracy depends upon how close the three closest masts are to each other. It's surprisingly accurate. This information is stored in databases and has so far never been deleted. It can be a bit of a project to find it. But it's all there for those who have the phone number.

A system can easily be set up where any incomming call on a specific phone will be traced and position triangulated. And all calls that phone has gotten from other phones will get similarly traced and people can be brought in for questioning.

The problem isn't technological at all. It's the legal bit. In Sweden the cops need a warrant and those are hard for them to obtain. It needs to be well motivated and can take a while to get. Phone companies are very wary about cooperating too readily with the cops. This data can be very sensitive to their customers so they only give out the bare minimum they're legally required to.

Another issue may be financial. IT professionals who know the techonology are expensive. The police aren't swimming in money and the talent are likely to work somewhere a little bit more lucrative. This means that even if they have all the technology and data chances are that it doesn't work quite as well as it theoretically should. A major factor in this is asking the right questions of the phone companies. They make a lot of mistakes.

You don't need the tracing to fail. The reality is that unless something close to a miracle happens, it's going to take at least a couple of minutes for the police to arrive on scene. Let's go through what happens.

The call comes in from a cell phone, and within ten seconds the computer spits out a location that's within a hundred yards of the person calling. The computer screen starts flashing a warning of what's happening at a human. The human notices the screen and processes the information.

The human than calls dispatch. Dispatch answers and again has to process the information. Dispatch then goes on the radio, advising units to respond to the location. Police officers in individual units have to process the information, determine how to get from here to there, and start responding. Then after using up time in travel (even if the unit is 200 yards away, it still has travel time), the officer has to assess the scene, which unless the person is standing there in the middle of the Mojave Desert is not going to stick out like a sore thumb.

Notice how much time ticks by in "ideal" circumstances. Even dealing out the dispatcher doesn't improve this a whole lot. But now factor in real world delays. The dispatcher is sipping a cup of coffee. The guy watching the computer is taking a leak. The nearest unit is a mile away. The location is completely unexpected (the first call is from Buffalo, NY; the second call is from Seneca, NY; the third call is from Eire, PA -- all easily doable for a kidnapping in Buffalo, NY).

All of these real world delays start adding up quickly. They're not much, but they're enough. And in the real world, as well as a novel, they cause frustration. You're just missing, sometimes by mere seconds, although usually by minutes. And there's not a damn thing you can do about it.

So you don't need to make the trace fail. Even when it works, it's easy for people to work around. Everyone knows you limit the phone calls to less than thirty seconds.

Best of luck,

Jim Clark-Dawe

callalily61 said:

I have kidnappers making ransom demands and giving drop-off info over cell phones. On TV, I've seen police set up wires and screens and computer-type paraphernalia to trace the calls.

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If the caller ID is valid, then 'tracing' the call is trivial; it may be 'blocked' at the phone, but the telephone company will still receive it and be able to pass the number to the police.

If the caller ID is faked, then you'd have to trace the call back through the system to see where it really came from, which could require interactions with multiple telephone companies in different countries. Note that probably does not require the call to be up at the time, since the companies should have logs telling them where the call was routed from.

But to fake it your criminal would need some tech skills because they'd have to somehow get the initiating telephone switch to send the wrong ID which would likely mean they would have to be working for the phone company or have hacked into its systems.

I don't know whether VOIP to PSTN gateways trust any caller ID information sent from the softphone or generate their own.

Drachen Jager said:

Yep, pretty much. If the criminals are that stupid. If they're above your average level of criminal intelligence they'll at least use a burn phone. This can still be traced to an approximate area and a phone number, but if it was purchased with cash they won't be able to find who owns the phone and if the criminals are smart they'll dump the phone or give it away to some homeless guy when they're done with it.

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Sometimes the police can refer to security video in some stores for image of the suspect. Investigators caught one nasty guy this way (who happened to be a correctional officer).