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Information to be sought from an expert

Stewart Bayles, prosecution, expert witness, challenge expert evidence, access to information, expertise.
An expert opinion is not just an end product. It’s not just a conclusion on its own. An expert has got to be able to show their workings. They’ve got to be able to show how they got there. They’ve got to be able to justify their opinion, to explain it, to demonstrate how they got to it. And you, as the defense lawyer, have a right to get access to these things because you have a right to challenge the evidence against your client. And you can’t challenge an opinion unless you know what it is based on. Unless you know how they got there.
Sometimes that report will be an extensive report stating opinions, detailing what those opinions are based on. And sometimes it may be a brief. It may be brief, simply stating the conclusion without any support or justification. One really important thing and what I want to explore in this video is encouraging you to start thinking about how you can get access to as much information as you can, about what went into the expert report. What lies behind the opinion, that is expressed in the report? What is the process by which the opinion was formed? What is the information that the opinion is based on?
So what I mean by this, and I’m going to suggest that there’s maybe five categories of information that you can request and try to get access to. The first one is information about the expert witness themselves. Their CV, their resume, their qualifications, experience. What study have they done? What was this study actually in? What is their area of work? Where have they had their experience? And the reason for this is, you may wish to challenge whether the expert witness really is a properly qualified expert, whether they are properly qualified in that field and whether the evidence they are giving is really properly within their area of expertise. This is something that you can’t just assume.
You shouldn’t assume that the opinion that is being expressed is always going to be properly within that witnesses area of expertise. At the very least, you need to check this and test it if necessary.
The second category of information, and this can be a really important one, is all communications between the police and the expert witness or between the prosecution and the expert witness. How was the expert engaged? Was there a request letter sent? What was the expert told about the case? What information were they provided about the facts of the case or the state of the evidence? And this is really important part, the question of what information the expert was provided with. And that has two parts to it.
The first part is an expert witness will always be acting on the information that is given to them. You need to know precisely what that information is. That information could be wrong. It could be disputed. It could be one version of a disputed set of facts in the trial. It could be incomplete. You might want to put to the witness if this piece of information were changed, would would that change your opinion? If this information was added in, would that change your opinion? The second reason why you need to know all of the information that was given to the expert witness is, was the expert witness given too much information, about the facts of the case, about the investigation?
Does the expert know what opinion the police want from them or what opinion would support the police case? And if they do, is there an argument that this could have influenced the forming of the experts opinion, whether consciously or subconsciously? Now, we should note there will always be a balance here. An expert will need to have enough information about the case to orientate themselves, so they can make sense of what they are being asked. So their opinion is useful, relevant and it makes sense to the reader. But there may always be a risk that an expert witness can become too close to the prosecution case and lose impartiality.
The third category of information that you can request and ask for is all of the notes that an expert witness may have made along the way. Notes that may show any calculations, any workings, any tests performed by the expert to arrive at their opinion. There may be notes of discussion had by the expert. If the tests were performed in a laboratory, there may be bench notes. There will be a file. It will show the continuity of exhibits. This may provide a basis to challenge the findings later on in court or to see if there are any other things that are discovered by the testing that are not revealed in the expert’s final report.
The fourth category of information that you can request is, are there any protocols or codes of conduct that the expert is bound by within their field? For example, a forensic pathologist who performs an autopsy on a deceased person will work for an organization. There will likely be protocols and codes of conduct within that organization. The fifth category of information that you might request is sometimes an opinion will be based on a body of literature or study within a field of knowledge or a body of knowledge that exists. It might be based on tests or studies performed elsewhere at a different time and revealed in publications within the field of study. Then you want to find out about those.
If there are articles published, then you want those articles, you want to get them and you want to read them for yourself. Because in my experience, it is not always a given that a publication cited will support the opinion being expressed in a report. It is not out of the question that you will find that the study was performed under very specific conditions. Its findings might be limited to the facts of that case, and its findings may not necessarily support the proposition that is being advanced in the expert report.

Having access to the information and material relied on by an expert is necessary to meaningfully scrutinise their report. In this video, Judge Bayles discusses the categories of information which must be available for proper examination for expert evidence.

In your jurisdiction, are there any guidelines for experts or court decisions on the information and material that must be provided along with different types of forensic reports? Share in the comments section below.

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Decoding Forensics for Legal Professionals

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