Technical evidence is a common feature in today’s criminal trials. Whether CCTV footage of an armed robbery, paedophilic images stored on a computer, or text messages recovered from telephones seized as part of a drug conspiracy – electronic evidence may have a profound effect upon the proceedings and be fundamental in establishing innocence or guilt.
The investigation, analysis, and presentation of findings to the court is conducted by a subject matter specialist; an individual that is known in a legal sense as an ‘Expert Witness’.
The concept of using specialists in English courts to assist the judge and jury can be traced back to a litigation matter in 1782 that was concerned with the silting-up of Wells harbour in Norfolk. The court heard oral testimony from a leading civil engineer; Mr John Smeaton, and was guided by his insights into the evidence.
Whilst the practice of seeking advice from independent specialists continued over the decades, it was still considered something of a rarity; exemplified by the comments of Lord Justice Patrick Devlin who was overseeing the Old Bailey trial of suspected serial killer Dr John Bodkin Adams and commented in his summing up that “it is a most curious situation, perhaps unique in these courts, that the act of murder has to be proved by expert evidence.”
The concept, function and responsibilities of an expert witness have been clarified over the years and formally expressed in the Civil Procedure Rules 1998 (CPR), which hold that this designation must be reserved for an individual who has had specific training, education or experience that will permit them to provide authoritative commentary on evidence. Ultimately the expert may be considered an agent of the court and under the Criminal Procedure Rules 2010 (33.2) this “duty overrides any obligation to the person from whom he receives instructions or by whom he is paid”.
It is the responsibility of the presiding judge to consider whether an individual may be considered an expert witness for the purposes of the court. Generally a two tier test; as adopted in R v BONYTHON [1984] SASR 45 is applied: (1) whether the subject matter of the opinion falls within the class of subjects upon which expert evidence is permissible; and (2) whether the witness has acquired by study or experience sufficient knowledge to render his opinion of value to the court.
An important judgement from R v GOKAL (Court of Appeal, Criminal Division, 11 March 1999) clarified an important question as to the admissibility of evidence where the bona fides of the specialist were not in question but a concern may be raised as to independence. It was decided by the courts that in such circumstances evidence should be heard, though the ‘weight’ and importance must be considered carefully by the judge and the jury must consider the ‘weight’ and importance carefully.
In criminal proceedings in the United Kingdom it is common for both the Crown (the party advancing a prosecution) and the defence to instruct expert witnesses to assist their respective case preparations. In certain circumstances both sides may agree on the instruction of a single specialist, a ‘Single Joint Expert’ (SJE), however, whilst this approach can simplify matters and reduce costs it does introduce the risk of eliminating any peer-review of the conclusions. As a result the selection of a truly independent expert is of paramount importance.
Where separate experts are involved in proceedings the court encourages the it is encouraged by the courts for these parties to impartially assess the evidence and produce a witness statement or expert report. These documents must outline their respective qualifications/experience, the matters they have been asked to consider, their methodologies used, their reliance upon any scientific principles, their tests, findings, and the conclusions they draw.
The expert witness is privileged to be permitted to pass opinion; though it should be qualified and based upon the evidence and their interpretation of such.; t These statements or reports become evidence in the trial proceedings and so it is important that their content is clear, balanced, and can withstand scrutiny. Having considered the expert report served by a third party, the instructed experts are advised to meet and discuss their evidence in what is known as an ‘expert conference’. Often these meetings are held in strict confidence without the presence of the legal teams in an effort to encourage frank and open dialogue. As is said in the Russian proverb: “doveryai, no proveryai” (trust but verify). The intention is to allow the specialists to review the evidence, find areas of common ground, and narrow the issues for consideration by the court. The net result is to produce a jointly signed statement that details the evidence, any interpretation of the findings, and where any difference of opinion may feature.
In extremely serious proceedings the trial process may be temporarily suspended to allow the experts to consider the evidence, formalise their results, and attempt to secure a level of agreement (R v DAVIES & ORS; money laundering and drugs conspiracy [2008, Liverpool]).
The old adage of being “only as good as your last case” is often heard in the legal community. This is acutely true for the expert witness. Reputation and integrity are extremely important and a single finding of fault by a judge can dash all career prospects. Where an individual’s independence or expertise has been called into question it is common for the governing body for that industry to consider disciplinary proceedings. Where an individual has been found to have misled the court criminal proceedings can be instigated for perjury or perverting the course of justice. It should be noted that in the eyes of the law perjury is considered one of the most serious of offences as it is said to strike at the heart of the justice system (R v ARCHER [2003] 1 Cr.App.R. S 86).
The pillars of education, experience and certification are cornerstones for establishing a reputation as a specialist that may be called upon as an expert witness. These must be tempered with personal traits of professionalism and unquestionable integrity. For technology professionals, a relevant degree is considered a must and may be complimented by a masters or doctorate in the field of specialism. Certifications also hold an important place – whether vendor neutral, such as the ‘Certified information Systems Security Professional’ (CISSP), or relating to a specific technology – providing a level of assurance as to competence in a field.
However, textbook theory and paper qualifications are no substitute for experience at the ‘coal face’; it is common for technical forensic analysts to spend several years in a junior capacity at an established laboratory assisting qualified specialists in their assessments. They may work on several hundred or even thousands of cases before they can be considered by their peers to be competent to conduct evaluations on their own.
Once an individual has significant and verifiable experience, they may undergo vetting by an independent body such as Sweet & Maxwell, the Academy of Experts who conduct peer-reviews on applicants by established experts in a field and document successful candidates on an ‘Expert Witness Register’.
Once an individual has significant and verifiable experience, they may undergo vetting by an independent body such as Sweet & Maxwell, the Academy of Experts who conduct peer-reviews on applicants by established experts in a field and document successful candidates on an ‘Expert Witness Register’.
Summing Up
Finally, the aspiring expert needs to secure significant court room experience – being admitted by the trial judge as an expert witness, having evidence critiqued, and oral testimony subjected to cross-examination.
A career as a digital evidence expert witness can be rewarding, fascinating, and frustrating in equal measures! Individuals with acute attention to detail, true depth and breadth to their understanding, and a desire to make a difference may find it appealing. Long hours, exposure to emotive subjects and confrontation are also realities of the industry. It can also be an intimidating and a lonely field – at the end of the day there is only one person in the witness box. “Caveat expert” – let the expert beware.
Finally, the aspiring expert needs to secure significant court room experience – being admitted by the trial judge as an expert witness, having evidence critiqued, and oral testimony subjected to cross-examination.
A career as a digital evidence expert witness can be rewarding, fascinating, and frustrating in equal measures! Individuals with acute attention to detail, true depth and breadth to their understanding, and a desire to make a difference may find it appealing. Long hours, exposure to emotive subjects and confrontation are also realities of the industry. It can also be an intimidating and a lonely field – at the end of the day there is only one person in the witness box. “Caveat expert” – let the expert beware.
