←All Posts Posted on October 24, 2014 By admin
There’s an old joke which says that the definition of ‘expert’ is derived from ‘ex’ – meaning a has been, and ‘spurt’ – meaning a drip under pressure. In the legal world though defining an expert is rather more serious.
Similarly an opinion, in most cases, is simply whatever an individual thinks. However, the law likes to deal with facts which means that opinion can be something of a dirty word. Expert opinions are a different matter and are often called on when legal matters deal with specialist areas. Let’s take a more detailed look at when an expert opinion is allowed and what sort of person is qualified to provide it.
Since legal cases deal mainly in facts, merely expressing an opinion isn’t usually allowed, but there is one major exception to this and that’s where an expert of some kind is involved. These experts are usually drawn from scientific or technical fields, though it’s not unheard of for, say, art experts to be called on in cases of forgery. Experts, then, can come in various kinds. In cases involving complex IT matters for example, a computer forensic expert may be called on to offer a professional opinion on the technology involved and how digitally stored records relate to the matter at issue.
This brings us back to needing a less flippant definition than the one we started with of what makes an expert. An expert in a legal matter is someone who has acquired specialised knowledge in a particular subject area. An expert needs to be someone who has relevant qualifications or training in the field. This might be via membership of a professional body or by having undertaken a relevant industry training course. It’s generally also required that the expert has undertaken a relevant course of study – such as a degree or doctorate. They also need to have extensive experience in their field – usually 10 years or more.
Opinion vs Fact
What makes the business of delivering expert opinion tricky is that even though it isn’t in itself fact, it needs to be based on fact. In other words, the factual knowledge of the expert has to provide a firm basis for the opinion being stated about the case.
In general the law in Australia, in the form of the Uniform Evidence Act, recognises that an opinion is not admissible in order to prove the truth. However, there are exceptions to this, the important one here being that the so called ‘opinion rule’ doesn’t apply to evidence of an opinion which is based wholly or substantially on ‘specialised knowledge’ (this is set out in Section 79 of the Act).
When presenting the opinion this may require some sort of demonstration or explanation to be provided of how the expert has reached his or her conclusion. This leads to another issue in that the explanation needs to avoid technical language and be couched in terms that the rest of the court can understand, but we’ll come to that problem in more detail later.
When an opinion is offered, a judge needs to be satisfied that the expert’s knowledge and experience relates to the facts of the case. Also that any opinion presented is confined to the specific field of expertise and doesn’t stray into other areas. This usually means presenting the expert with clearly defined questions to answer, questions that are relevant to the case in hand.
In Australian law there are five key principles that determine whether expert opinion is admissible within the general requirements of admissibility and the Uniform Evidence Act:
Selecting an Expert
Experts have a big responsibility and it’s therefore important that they’re carefully chosen. Experts giving their opinion in legal matters are often from medical or scientific backgrounds and may be acknowledged leaders in their field from universities or other academic institutions.
Computer forensic examination being a relatively new field, expert opinion is more likely to come from specialists in examining and gathering information from computers. This is a task which requires particular skills, the volatile nature of some digital storage methods means care must be taken to ensure that data isn’t corrupted in the process of examining the system. A computer forensic expert will know how to extract information without compromising either the extracted data or jeopardising any further research.
The newness of the field also means that there are relatively few people with formal qualifications. It will therefore be necessary to look for experts based on their experience in working with systems on a forensic level.
Presenting Expert Reports
Sticking to the above rules means that expert reports must be presented in the correct way in order not to fall foul of the law. The central concern here must be to present an opinion on clearly defined questions, based on the specialised knowledge of the expert.
The report, therefore, needs to identify the facts on which the opinion is based as well as explain the reasoning used to reach the opinion. It also needs to be confined solely to the expert’s specialist area. This means including in the report details of:
Any items referred to in the report, such as documents examined or used in the research must be available for examination by other parties on request. If for some reason the report hasn’t been fully researched, perhaps because time was limited, it must say so.
The report also needs to set out the qualifications of the expert and list any references to other works used in forming the opinion – text books or accepted industry standards for example. If other people have been consulted in the preparation of the opinion they too must be identified along with their qualifications.
If any assumptions have been made in creating the report these must be clearly set out too, and if there are multiple opinions the report must provide a summary. Reasons for the formation of each opinion must be given and finally the report must be formally declared as complete.
If a mistake is spotted or new facts come to light after the report has been submitted these must be declared through the legal representative as soon as possible.
Avoiding Geek Speak
The problem with experts in any area is that they tend to deal with very complex subject matter that often has its own terminology. This can be particularly true in the computer forensic field. It’s important therefore that complex technology matters are explained accurately but in a way that non-experts will be able to understand.
This means delivering the opinion in plain English rather than in technical language as far as possible. Of course some technical information will be inevitable, but technical terms need to be explained along the way or referenced in a glossary so that they can be easily understood.
It’s important to strike the right balance here, as although computers are an increasing part of many people’s everyday lives, some of the terminology isn’t widely understood. Often the correct technical term for something is not in universal use. For example many people will refer to a ‘hard drive’ as the PC box which stands next to their desk rather than the storage component of the system. When in doubt it’s best to spell out exactly what’s being referred to even if this results in the document being rather wordier in form.
In short what all of this comes down to is that an expert opinion must be from someone who knows the field well and can deliver an opinion based on facts. Information must also be provided on how the opinion was reached. Finally the opinion needs to be presented correctly and in a way which is understandable to non-technical people.