Saturday, November 04, 2006

Mobile Telephone Evidence

GSM radio coverage bounces backward

A characteristic of radio signals is that they reflect off surfaces. Not startling or new news in itself, unless one considers its impact on radio coverage propagated North, but due to reflection, can be detected for instance in the South East or South West, behind the Sector of the Mast. In yet another case, I am told that at the Central Criminal Court evidence in a case confirmed that coverage in the opposite direction from its angle of propagation was detected and useable. It is useful to know this in cases for instance where the location of a mobile 'phone and a Cell ID's radio coverage at a location are not compatible with the investigation evidence. Importantly the case does not set a universal principle, as this phenomenon does not happen in every case due to flat earth, no clutter etc. Tests will still need to be conducted on a case by case basis. It does though cast doubt over simply conducting spot-tests at one location.

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