Data Usage in Cell Site Analysis

Data Usage in Cell Site Analysis

There are numerous common mistakes that can be made when conducting cell site analysis, and a mistake becoming prevalent when dealing mobile data usage is the error of using Distance-to-Mast (DtM*) instead of using Distance-to-Usage Parameters (DtUP*). With mobile data usage on the increase and with wireless WCDMA, but equally LTE, will start to break the monopoly of landline internet usage by 2016 (that is four years time) those producing evidence and Judges looking at evidence in Court really need to be aware.
        
*copyright (c) GSmith 2005-2012

Disclosure to Defence, Opinion and Bayesian Statistics

Disclosure to Defence, Opinion  and Bayesian Statistics

The reported outcome from the trial and appeals of R v Adams ( [1996] 2 Cr App R 467, [1996] Crim LR 898, CA and R v Adams [1998] 1 Cr App R 377, The Times, 3 November 1997, CA) rulings was the Courts ousted explicit Bayesian statistics from the reasoning admissible before a jury in DNA cases. However, calculating the probabilities for say cell site analysis activity/location, partial recovery of a file's data and its likelihood to being a particular image etc using Bayesian, I do not to suggest that this case disbars individuals from using it in their analysis. Importantly, the case opens the doors of transparency in relation to revelation of previous consideration about its use for evidence, what measures the person has been taken to prevent assumptions about unproven facts implied as accurate and so on.

To assist the transparency principle, it should be understoood a fundamental tenet of forensics is the practice of open, free and frank discussion and disclosure about pitfalls, flaws or unsolved errors in practices, process or procedure should not be avoided.

To illustrate some ideas of lacking in transparency.  If an examiner uses eg machinery that is out of date or flawed in its operation, then clearly it is not the manufacturer that is at fault. The examiner applies the use of the machinery to obtain, produce or treat the evidence. The examiner, it is expected, who uses the machinery should understand the technicality and science in which they are involved and be able to determine in advance of the machinery use its capability (drawbacks/limitations) when assessed against known facts and requirements. Moreover, to warn about issues if the machinery then produces random output upon which its user then decides to opine statistics, probabilities and theorems being drawn from the output of the machinery.

To suggest two of many cases where we may apply the above illustration:

Case 1: would the occurrence of a mobile station using a particular set of Masts in a four hour period suggest the MS was within a defined area? The radio test equipment used to conduct tests would be unable to confirm if the operator uses "directed retry" as to an MS's call history, as the radio tests conducted are post event. The knowledge the user of the equipment must have is where to get that information if it cannot be obtained from the test results?   Without knowledge of directed retry to produce statistics about occurrence could amount to opining random speculation.

Case 2: IPhone is a popular smart phone. The release of iOS5 introduced 'iMessaging' - a messaging service for texts, emails etc using the cellular network or WiFi as the transport paths to communicate messages. 'iMessage' falls under the iPhone Message App which is equally shared with 'SMS text messaging' - which is only sent over the cellular network. An interesting feature with iMessage is that messenging with another iOS5 device it highlights the message in 'blue'. Moreover, where the user's iPhone uses a previous OS (iOS4 or earlier) the messages appear 'green'.  However, a further distraction from the straightforward blue/green operational scenario is where an iOS5 device communicating to another iOS5 device using iMessaging starts off in blue but then turns to green? Avoiding the issuesassociated with identity and origin, there are huge possibilties to spend hours calculating or producing statistics about the content of a message, but what happens when consideration is given to the blue/green paradox and the handset reading software tool fails to identify detect which messages are blue or green?

At the top end, using quantifying techniques like Bayes to opine a theory from which a conclusion can be drawn can be fraught with flaws in the absence of knowledge, skill and experience about the science subject matter in which the person works. The same can be applied at the other end, by avoiding those with knowledge, skills and experience for simple platitudes, dumbed down evidence or psychologically trickery (getting others to do what you want them to do) to avoid answering the question can lead to the production of a philistine opinion/conclusion.

Turning to another point about this case. A useful influence that has also been reported that arose in this case during the various hearings and appeals apparently led to both experts required  to consider the expert findings in order to respond to two fundamental questions. In order for that to be achieved "The scientist adducing the 'DNA comparisons'  should do so with his calculations of the random occurrence ration. Whenever such evidence is to be adduced, the Crown should serve the defence with details of how the calculations have been carried out, sufficient to enable the defence to scrutinise the basis of the calculations. The forensic science service should make available to a defence expert, if requested, the database upon which the calculations are based."

If we are to reflect how the need for proper and transparent disclosure and the equal treatment of the defence expert may be put into practice for calculations and databases, examples could be expressed as:

Handset and SIM/USIM Data Acquisition - complete acquired (not partially acquired) data in those devices to be disclosed to the defence; disclose report and identify standards etc and any opinion formulated

Cell Site Analysis - disclosure of radio test measurements, surveys, materials from relevant mobile network operator/s and confirmation of all material considered and disclosed (including handset/SIM report; call records; cell site etc)

Call/Billing Record Analysis - disclosure of billing, CDRs, TAP and IRA/IOT roaming records, IMSI/IMEI analysis, voice and data usage etc

As cases, like Adams, do not appear to have been overruled for upholding established principles, it would be odd to see them overlooked in times of economic cutbacks: eg " a good day to bury bad news " approach were it to be inferred or implied:

- disclosure to be costly,
- causes difficulty to those who seek to simplify evidence because they do not technically understand the evidence (and the logical and natural consequence of the latter),
- the dumbing down of evidence.

A strong supporting tenet in the doctrine of disclosure is the linked parallel requirement for appropriate and necessary experience and competence of the expert to deal with the compiling or assessment of the evidence. That is, as opposed to an inexperienced or less experienced person or a person indirectly involved in the science/technology element of the evidence being encouraged to have a stab at interpreting the evidence.  Such examples, where society would most probably find the latter notions abhorrent were they to be practiced by one party or another, and quite rightly so, can be suggested as:

a) an anesthetist assisting a brain surgeon in theatre (thus working in close proximity, similar as one may do in a company) :- should the anesthetist be asked to opine about surgically gaining access to a brain tumour or the likelihood of the success/failure of such surgery?

b) a barrister who has dealt with 40 cases of dentist mistreatment should s/he be asked what procedure is needed for removing impacted wisdom teeth or the likelihood of success/failure of removing the impacted teeth?

c) the analogies above applied to persons involved with DNA, blood sampling, fingerprinting and technology evidence etc... may equally draw opinion on a view society may take?

d) where the person being asked to give opinion has far less experience is preference over highly experienced persons? 

The discussion in this thread is not to argue or advise on law (as I am not holding out to do so), nor am I qualified in this area, nor am I suggesting seeking the advise of anyone other than those who are highly experienced in eg law. The discussion is to identify a case and expose how it can highlight unnecessary challenges placed on the standards and quality of evidence that may arise, introduced by poor opinion or opinion generated from over-confident attititude of inexperienced or less experienced individuals. 

Additional case reference: R v Doheny and Adams [1997] 1 Crim App R 369.

UK Criminal Evidence Delays

UK Criminal Evidence Delays
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Due to delays in passing evidence to the defence certain building blocks of evidence used against a defendant are not being held by the prosecution, but worst still, the expert who obtains, for instance the tests and results, holds on to them because they claim their client (the Police) haven't made that a term of the instructions to pass them over. The police say they don't need to have it because the expert hasn't said it's necessary so they wont ask for it.
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So what makes me and others think that we should expect, as a requirement, all the mobile telephone/cell site analysis evidence upfront from the prosecution and why do we think, as a requirement, the prosecution have a lawful duty to have obtained all the evidence from their expert, in order to meet the first requirement?
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It is the lawful duty, so we are told, of the prosecution to look at, examine and retain a copy of all evidence (e.g. tests and results) and to conduct an assessment of risk, which is the principle enunciated in the "Golden Rule" by none other than Lord Bingham.
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Examiners/Experts at common law are no longer entitled or permitted to arbitrarily withhold any evidence from their work in a case but are required to produce to the prosecution an index of all used and unused material they are holding which should replicate the actual physical copy of evidence given to the prosecution. So for a case involving mobile telephone/cell site analysis that would mean:
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1) written instructions of work to be undertaken
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2) call records/subscriber details
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3) cell site details and data
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4) GPS/CCTV evidence
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5) handset/SIM (USIM) data and report
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6) copy of the actual radio test measurement results obtained at site and presented in a visible, legible and intelligible format (with the electronic file of the original radio test measurements to accompany them)
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7) copy of the expert's analysis of the results, report and any supporting exhibits
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8) copy of written questions to and written responses from the mobile network operator
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9) material considered and unused material and/or material disgarded as not relevant
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.......and so on.
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This enables the prosecution to sit down and examine what is on file put before them by the examiner/expert (usually the data can be recorded onto a CD costing less than £1.00) and all the material on CD and/or in paper form are identified on a tick sheet. The prosecutor/prosecution should then avail him/herself/themselves of the knowledge of that material by familiarisation with the information on the CD and/or in paper form. As some information may not be readily understood the examiner/expert should be called (by phone, written or in a meeting) to explain material or information not understoood. The risk assessment can then be made.
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It is equally understood that the right of the defence to investigate the evidence held against a defendant was and is to stop cases being brought against anyone where evidence was being withheld, in a deliberate or clandestine fashion, in order to meet the principles of ECHR (Foucher v France). No evidence on file can be withheld from a defendant and no steps should be taken to find mechanisms to avoid holding or hiding evidence from the defendant. For the avoidance of doubt, I am not referring to public interest immunity (PII) information, which is another matter entirely.
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So it is easy to see the principles enunciated by Lord Bingham in the Golden Rule contain impeccable logic and foresight. The Golden Rule requires the prosecution to logically assess that it has a complete copy of the evidence e.g. tests and results and if they were not held by the prosecution:
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A) How would it be possible for the prosecution to conduct a risk assessment without the full evidence made available to them from their examiner/expert?
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B) What happens, for instance, if the examiner/expert dies and no one can find the test results?
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.... and the list goes on.
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So what are the current delays? Whenever asking for standard mobile telephone evidence, for instance items such as cell site radio test measurement data or ask for corroboration of enquiries to and written responses from the mobile operator, the prosecution do not readily hold the evidence and massive delays ensue until just before going before the Judge part of the evidence suddenly emerges and then the defence are left to hurry an examination of that evidence.
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I have a case on right now where I requested evidence on the 6th March 2009 and apart from the prosecution correcting mistakes in their material which the defence had to point out to make any sense of what the prosecution's evidence was meant to mean, the other corrobating information expected to be found in the file or CD under the Golden Rule principle and could/should have have been disclosed up front in March, this still has NOT been served. For instance, the radio test results have still not been served along with other information.
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These delays impact by causing problems for the defence in many ways. Some examples are:
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i) Defence experts are expected to tidy up the technical errors and mistakes (not typos though) with the prosecution's evidence. This implicitly means though that defence experts are acting as quasi-prosecution experts. These errors and mistakes are red-herrings though and occupy defence time to put them right, so by the time the requested evidence comes through the trial date is upon us and then the defence have limited time to conduct a proper and orderly analysis, which implicitly means the defence are equally being cajoled into overlooking some evidence or make mistakes due to being rushed.
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As a side matter that is also concerning. If by chance some were to suggest that the observation about quasi-prosecution experts is not true, then consider this. If defence experts were to write reports delivered at court before the jury identifying all the inherent technical flaws and what evidence had not been served or served late just before/at trial, a defence expert would be more likely to get a reprimand from the Judge for wasting time and for not raising it sooner. In the alternative, the prosecution would go away correct the mistake and put version 4 of the evidence before the jury. It still means the same thing though, that defence experts are being placed into the position of acting as quasi-prosecution expert because the work they do identifying those corrections will be used against a defendant. My natural instincts tell me this is an appaulling breach of human rights. It will take someone with a far greater mind than mine, maybe even Lord Bingham, himself, to put that in the appropriate legal context highlighting that injustice in the current criminal evidential procedures.
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Additional note: When mentioning human rights and injustice, my comments are not intended to campaign to get criminals off, my intentions are clearly about the rules that define how evidence should be presented and the roles people play in that process and about evidence generally. It is also about safeguarding our rights, our childrens' rights and our families' right to a fair trial in Britain, as opposed to deciding who gets the better court case based upon who understands what evidence should have been presented at the outset.
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ii) The discussion being raised is not about where mobile telephone evidence suddenly becomes relevant just before or during a trial and taking everyone by surprise, it is where the evidence has already been examined and the delays to present the evidence to the defence means changes that can be happening in the radio network or the operator deletes data after a period of time prevents the defence from pursing lines of investigation of their own or conducting tests. The delays muddy the waters for the defence to properly do their job.
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iii) Where the defence expert is prevented from knowing the weight of the technical case against a defendant it means the defence expert cannot properly advise the defence solicitors. More importantly this handcuffs the defendant from knowing the prima facie case against him or her.
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iv) Another matter which is causing headaches: by the prosecution's actions of delaying service of evidence which they already hold (Golden Rule requirement) but they choose not to disclose for months on end impacts as defence experts cannot afford the time locked to a case over a long period. More importantly, as cases that run for months and months means the defence expert is not being paid until the end of the case it is just not financially viable for the defence expert to take the work. Consequently defence experts are being driven out. It should be noted also defence experts have no powers to demand evidence, we can only ask. This means that we are left to correct the prosecution technical errors and point out in advance the missing evidence (see - i) quasi-prosecution expert, above).

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These evidential delays have not just started but have been going on, and with increased regularity, long before the recession started, so the recession is not the reason for the delay occurrences. The delays are not stated in procedural requirements and are not stated to be accepted because they (the delays) are usual, standard practice. The remedy to make these problems to go away is absolutely clear and easy to achieve and that is for the prosecution to stop the delays in serving evidence and present it up front, without delay, in every case using the Golden Rule evidential acquisition process needed in order to conduct a risk assessment. The CD/paper work can then be immediately passed to the defence without delay.

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UPDATE

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Just wanted to add an extra piece to this discussion that I had considered when forming my observations.

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The case in point deals with fairness, not simply from a defence view point but prosecution, too. When requesting evidence it is a 'requirement' of the defence expert (thus defence) if, during examination and analysis, there is something wrong with the evidence or there is evidence missing that the defence expert should ask for it no matter how late in the day.

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That is because if the defence expert doesn't ask for it the defence cannot request it and it could lead to an unfair trial. So when it is thought I am giving the prosecution a hard time over requesting evidence and asking them where is this particular piece of evidence that they would naturally need in order to know whether, say have the Masts changed or not before testing, it is not my intention to make someone look bad, or imply they don't know what they doing or in some way create difficulties.

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As an expert there is a requirement to inform the defence, whether they like it or not, tedius or not, the expert must put it to them and seek the evidence or understanding about the evidence. That is because it is the duty of the defence to raise it to the prosecution so that prosecution are given a fair chance to deal with the request.

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For the discussion in this thread it took account of the Gleeson principle, which I record below.

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Testing the evidence: In our adversarial system, the defence, of course, are entitled to exploit adventitious faults and failings by the prosecution. Auld LJ in his Report of the Criminal Courts Review incorporated into his judgment in the case of Gleeson [2003] EWCA Crim 3357 at paragraph 36, in which he said:

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"To the extent that the prosecution may legitimately wish to fill possible holes in its case once issues have been identified by the defence statement, it is understandable why as a matter of tactics a defendant might prefer to keep his case close to his chest. But that is not a valid reason for preventing a full and fair hearing on the issues canvassed at the trial. A criminal trial is not a game under which a guilty defendant should be provided with a sporting chance. It is a search for truth in accordance with the twin principles that the prosecution must prove its case and that a defendant is not obliged to inculpate himself, the object being to convict the guilty and acquit the innocent. Requiring a defendant to indicate in advance what he disputes about the prosecution case offends neither of those principles."

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Some important words there are "....once issues have been identified by the defence statement....." and "Requiring a defendant to indicate in advance". How can that be done if the defence expert has seen errors or omissions in the prosecution evidence but then goes on not to ask for those gaps to be filled?

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The problem here will be that where evidence is trickle fed to the expert s/he will always be tactically put on the back foot so as not to catch up, thus potentially failing the principle whereas if all the evidence is disclosed up front would that problem still exist?