Mobile Phone Forensics – A Brief Introduction
Mobile Phone Forensics or Cell Phone Forensics are improving daily. These services are now commercially available through certain specialist companies, (Mobile Phone Forensics, (
These days, along with the computer, mobile phone forensics is the police officers first point of call. Where are you likely to record everything? Where are the records of wrong doings going to be stored? Even if you are not the sort of person to record wrong doings, human nature states that you will tell at least someone. On a computer, they could be stored within your PST file,(Microsoft Outlook personal storage file), your EDB file, (Microsoft Exchange storage file), your NSS, (Lotus Notes), your MSG, (Microsoft Outlook Express), and your EML, (generic email files), amongst others. All these records are kept digitally on various storage devices, be they mobile phone SIM cards, perhaps mobile phone 3G USIM cards, the generic mobile phone memory or internal memory cards; mainly MMC memory cards, but not exclusively. Nowadays, the forensic investigator does not have to solely rely on his mobile phone investigative resources, but has to have a sound knowledge of evidence handling, write-blocking and general computer forensics, to ensure that a full examination of all available data has been achieved for the client in a sound and forensically correct manner.
A more recent development in this technology is the cellular transmitter location, which is used to assist agencies in pinpointing the approximate whereabouts of the investigated. This sort of investigation technique was first used in a very high profile case in the United Kingdom, namely the murder of two young girls in a town called Soham called Jessica Chapman and Holly Wells, (
"If the automobile had followed the same development cycle as the computer, a Rolls-Royce would today cost $100, get one million miles to the gallon, and explode once a year, killing everyone inside."
- Robert X Cringely
This type of thing is probably best submitted as an article rather than a forum post, unless it's specifically posted for discussion. If you'd like to submit an article please contact me (you will still be able to include your company's contact details).
Jamie
Cellular transmitter location has been around for years. It was actually used in the OJ Simpson case back in 95, and the military and intelligence communities have utilized it in some form for a while. The concept isn't a new one, rather the results have been getting better as the mobile phone networks have upgraded their kit and made more efficient use of the frequencies in order to aid triangulation.
Also, if somebody managed to make multiple clones of a SIM card including all of the relevant phone etc identification numbers, wouldn't that cause problems for caller location as you've now got multiple copies of the same phone on the same network? I'm not an expert on SIM card cloning so I don't know whether this can be done to this degree– just a thought.
results have been getting better as the mobile phone networks have upgraded their kit and made more efficient use of the frequencies in order to aid triangulation
Just out of interest does anyone know how accurate this type of thing is nowadays? How accurately can a position be established and what effect, if any, do environmental factors (buildings, weather, etc.) have?
Jamie
I've done a little digging into this subject and the general consensus is that cellular tracking isn't that accurate if you use the native infrastructure of the cellular network itself. Firstly the network, with its 'cellular' design, contains gaps between cells where the user experiences no signal or coverage and will therefore be blind to the network. When you consider building penetration the coverage drops off severely as the cell network uses relatively low power transmitters that are highly inefficient at penetrating man made structures. Also, according to what I've read, you only need one transmitter to support a phone call and three to perform triangulation, in some locations you cant get a signal or you get a very poor one, a good indication that you're probably not under the coverage of three transmitters. Having said that I know that some of the newer phones are, or soon will be designed with GPS chipsets which will utilize the GPS satellite network which can provide highly accurate positional information. Even this will have limitations though because there must be a relatively clear "line of sight" between the receiver's antenna and several orbiting satellites. Anything shielding the antenna from a satellite can potentially weaken the satellite's signal to such a degree that it becomes too difficult to make reliable positioning, and a savvy criminal can always work out how to disable such incriminating features anyway. One important point I would like make though is that the above information pertains to commercial location systems or the use of the commercial infrastructure to locate a handset, I know, as does anyone who watches the news, that the military have exceptionally powerful antennas that have successfully been used to triangulate calls and subsequently apprehend criminals. So I guess the answer to your question regarding accuracy is that it depends who is doing the searching.
Nice one, fat rabbit, interesting stuff.
Jamie