All I know is that the phone conversation has to last for like 30 seconds - according to some movie or television show I watched one time - where they had to keep a guy on the phone for 30 seconds until they could trace him. After that, I'm guessing they are traced.
Your not gonna get an exact answer for this or a completely correct one, nor if you did would you be able to put that information in your story as its classified.
The phones aren't classified the capabilities of the instruments and programs that do this are. And yes they very much are so before you go trying to call me out on what I do for a living, maybe do some research. Oh and by the way the NSA isnt sitting around listing to your phone calls, they have more important things to worry about.
Cops/FBI/CIA/etc do not instantly start tracing a phone call the moment they pick up the phone. When I said unless they were expecting the call, I mean like in a case where they are helping a family whose child was kidnapped and are waiting on a call from the person demanding ransom. Then they'll start the trace shortly after the phone is received. Starting the trace on every phone call the moment you pick up the phone is an incredible waste of resources and pc power.
After doing some research, it appears that if you dial 911 from a land line in the United States, there is a system called an "automatic location indicator", which immediately tells the person answering the phone where the call is coming from. The location comes from a database, that means that there is no tracing going on. If, however, the database is faulty (which can happen), then there is a chance that the location will remain unknown, or it is mistaken. Most amusing. Of course the capabilities agencies like NSA etc. provide for this are classified. That is not surprising, seeing that even the lunch menu at secret service canteens is classified. That does not mean a writer can't describe a lunch at Langley.
I think the old phone systems with mechanical switches needed to be traced manually - that's what you're seeing in old movies when the police officer says, "Try to keep him on the line! We need 20 more seconds to trace the call!" New phone systems are computerised and simply store the number you dialed in a log file. Even if the call only lasted one second, the police can check it up a month later. That's why your phone bill can list all the calls you made. Here in the EU, phone companies are required to save their log files for at least six months. I'd be surprised if there weren't similar rules in the USA, especially considering the fear of terrorism. Special police and intelligence agencies don't have time to manually listen in on all phone conversations, so they use the log file data (who called whom) to draw maps of people's social networks (so called sociograms). That way, they can see who has connections to a criminal, and guess at how criminal networks are built up. It can just as easily be used to keep track of dissidents and information leaks, of course. There was a scandal in the USA a few years ago when the government had collected and analysed the call data for several hundred million American citiizens without authorisation.
It depends. It's different for land lines and for cell phones. And, for cell phones, the location of the phone being tracked matters somewhat. It also depends who is doing it and for what. The police can't trace a call as freely as the Department of Homeland security. Homeland Security can trace a land line call instantly. A cell phone in a matter of seconds.
That's because 911 is an emergency system. They are set up to trace a call the moment they pick up. Even if you accidentally dial the number and tell them it was a mistake, they still send cops out to check on you. And making multiple false calls to 911 can get a person in trouble. The 'automatic location indicator' is more like Caller ID. It tells them who is calling and their address, but if the user is calling from a cell phone, it doesn't really tell them the location from where he is calling.
I don't think that's necessarily true. One time when I was a kid we thought my mom was having a heart attack. After we ran downstairs to see her on the floor clutching her arm, I yelled at my brother to dial 911. Maybe a second or two after he pressed the last 1, my mom told him to hang up the phone because apparently, she had slipped and scrapped her arm on the coffee table. My brother didn't even hold onto the call for a second and about 15 minutes later, a police officer came to our door stating that a 911 emergency call had been made and wanted to check up on things. This was almost 20 years ago. I'm pretty sure it won't take much to trace a call now. Cell phones on the other hand, are a different story.
