Location Forensics Expert Witness

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The question of 'where?' a person, device or vehicle has been located is now often key evidence in a range of serious criminal cases.  It can involve a range of digital forensic areas and one of Sam's specialisms, is being able to review location evidence including assessing its accuracy and also combining and comparing different forms of evidence.    SRC can assist you with:

  • Detailed analysis of use of devices/phones including location points stored on devices.
  • Information stored within Cloud applications including data such as that present in Google maps/location points.
  • Reviewing CCTV and ANPR data to compare with digital location evidence.
  • Cell site analysis 
  • The accuracy of GPS in the context of the data in your case.
  • Vehicle forensics including from telematics systems (inside the car) and trackers.
All instructions to SRC including for appeals are only undertaken via a solicitor, direct access barrister, law centre or corporate legal department. SRC does not accept direct instructions from members of the public due to case complexities, disclosure/data/privacy issues and strict expert witness rules. In such an instance, please provide SRC's contact details to your legal team. 

Due to Sam specialising in complex larger cases, she does not accept instructions in cases involving minor speeding offences.

Sam has not side-lined into location forensics, she is all about the question of where? - she has been receiving instructions in cases involving location evidence for over 17 years including working on early cases assessing GPS tracker software accuracy and storage of data, the accuracy of Global Positioning Service (GPS), electronic tags and Satellite Navigation units (Sat Nav) evidence, when these were emerging fields in criminal legal cases.   She also has worked throughout this time in early cell site analysis cases.  She has continued to work on cases involving location evidence throughout her career, expanding into the area of telematics (vehicle data) and also location evidence stored on smart phone handsets, particularly iPhones.

Sam now specialises in expert witness evidence in cases involving complex assessments of the limitations and otherwise of sources of location evidence, combining the sources of evidence to determine comprehensive chronologies of use, and comparisons between the various sources of location evidence (including for cases involving attribution or correlations/differences in use).   LAA rates are available.  Contact SRC with your instruction or review what information to provide SRC in a location-based case instruction.

Some further details about location forensics are discussed in the following (click on the drop-down arrow):

  • Mobile Device Location Storage

    Modern mobile smart phones (such as Androids and iPhone) may store a range of potential location-based information including WiFi point use, location estimations made by the phone (such as iPhone location points), logs of use of mapping application usage, health application logs (such as steps and floors climbed) and also even conduct their own WiFi and cellular scanning.    Where this evidence is present, it may exceed the ability of cell site analysis and in some ways, cell site analysis is the location evidence of last resort.  


    Although people may assume a device logs its IP address, the question of 'where?' evidence is rarely addressed by IP address assignment (which is sometimes wrongly assumed to be the only/key evidence to address this question since it may have been used to initially 'find' the devices).  


    Location evidence may also be present in general use and device data stored, for example, if there photographs from a particular area, users conversing about visits to particular locations or emails of bookings at X hotel etc.


    Most importantly, the accuracy of each source of location evidence is often crucial to consider, since although a mobile device may have a GPS receiver, the location evidence on a device may actually be approximating the location, based on the mobile and WiFi networks in the area or otherwise.  Hence, it is important to consider the limitations of what can be determined for each source in relation to the locations of a device.   It may also be important to combine this with other device evidence, such as the steps/health information and other interactions with the device even to the extent of if the phone is picked up, its screen lit up etc. which all may be logged.


    There may also be other forms of stored evidence such as application and Cloud location point data (see below).

  • Cloud Storage - e.g. Google and Google Maps

    Location data may be stored on a device from applications as well as stored within application and account use, for example, Google location and maps point storage.


    Such data is often not accurate, and needs to be fully assessed to determine what can and cannot be used and the limitations thereof.

  • Vehicle Trackers and Telematics

    Trackers may be fitted internal to vehicles by the manufacturer or after market as well as for insurance purposes (black boxes).    Cars may also now have synchronised applications provided by car manufacturers and data may also be stored directly within the vehicle itself (telematics).  In all cases, this information may used as evidence in cases in terms of the location of the vehicle and also interactions with it including things such as ignition events and even when doors were opened/closed etc. 


    As of April 2018, all new model type cars should be fitted with an eCall system allowing GPS location information to be sent to the emergency services via a tracker and SIM card unit fitted to the car. Hence all new model cars theoretically after this date will contain a type of tracker and SIM card. The SIM cards in the absence of other information, may also be used to perform cell site analysis.   


    Users may also use Satellite Navigation (Sat Nav) units which can also be examined in order to establish locations/journeys of use and the accuracy of this information assessed.   

  • Trackers - GPS Accuracy

    Sometimes location evidence is assumed to be derived from GPS, however, this is not always the case when it involves location points stored on phones and/or in Cloud data.   Hence, Sam will need to assess the origin of the data in order to evaluate its accuracy and limitations.


    It is also generally assumed that GPS and tracker devices are completely accurate.   However, there are various aspect to assessing this in practice, particularly when individual points are siginficant in cases.    


    Sam can firstly ensure you have the correct and original data source of your location data case, and then make an assessment of all of the data and the operation of the tracker system and GPS unit (or other origin of the data).

  • Selecting Best Source of Location Evidence

    Sam can evaluate the 'best' source(s) of location evidence, involving computers, routers and mobile devices, cell site analysis and trackers/vehicles (see above) including determining the accuracy of the evidence and combining the evidential sources. SRC can also combine/assess this evidence to determine its accuracy and to provide chronologies of locations and general device use. 


    Sam can also assess comparisons between certain souces of location evidence in order to assess evidence of attribution including correlations and differences in the use.    For example, comparing the location points/cell site analysis of a phone and the movements of a vehicle's tracker.

Instructing SRC in a location forensics case


Usually location forensics is a criminal investigation and SRC can combine the evidence of vehicle use, location based information on devices with cell site analysis to establish potential use of devices in/around vehicles on its own or as part of attribution evidence assessments.  Sam can also determine the 'best source' of location evidence available in your case.


When instructing or contacting SRC it is useful if you can initially supply the following:


  1. Trial date (including schedule time) and any Court or other deadlines.
  2. Statements and reports in relation to the technical evidence and seized digital devices.
  3. Any technical exhibits supplied so far including tracker data and/or call data.
  4. MG5 or case bundle.
  5. Details of defence/defence statement and/or instructions of what may be required.


Location forensics cases can pose issues in terms of what data is available and how it may be provided and evaluated.   Hence, SRC can provide you with initial reviews to assist with establishing what may be required and can provide assistance in what location digital evidence may be available and also how to obtain this evidence.


Sam may also take on a limited number of civil/family, matters particularly if they involve the investigation of a death or involve children.   Please provide details of your case when initially contacting. 

For details of previous cases in which SRC have been instructed involving location based forensics see Sam's previous case list.