Law and Rights
Courts frequently receive various types of "expert evidence." Sometimes it can have a very powerful effect and it is common knowledge that reliance on expert evidence has resulted in some serious miscarriages of justice. Indeed, many examples could be given such as the late Sally Clark (2003) and Angela Cannings (2004).
The Law Commission has published "Expert Evidence in Criminal Proceedings in England and Wales" (Law Com No. 325 - 21st March 2011). The Commission's Report contains many recommendations relating to the admissibility of expert evidence in criminal proceedings in England and Wales. There is also a Draft Bill - set out at Appendix A of the report (page 144). The Commission has stated: "Too much expert opinion evidence is admitted without adequate scrutiny because no clear test is being applied to determine whether the evidence is sufficiently reliable to be admitted" - see Law Commission for their fuller statement.
Admission of Expert Evidence - The Commission has proposed that expert evidence would be admissible in criminal proceedings only if certain tests were met:
might think that the first three bullet points are obvious. They are included because the Commission wished to put in a single piece of legislation all the relevant law relating to admissibility of this type of evidence. They key new feature is the proposed reliability test which is set out in Clause 4 and Schedule 1 of the Draft Bill.
A reliability test
The decision on reliability would be for the trial judge alone. Under Clause 4, expert opinion evidence is sufficiently reliable if (a) the opinion is soundly based, and (b) the strength of the opinion is warranted having regard to the grounds on which it is based. Certain matters could, in particular, provide a reason for determining that expert opinion evidence is not sufficiently reliable: (a) the opinion is based on a hypothesis which has not been subjected to sufficient scrutiny (including, where appropriate, experimental or other testing), or which has failed to stand up to scrutiny; (b) the opinion is based on an unjustifiable assumption; (c) the opinion is based on flawed data; (d) the opinion relies on an examination, technique, method or process which was not properly carried out or applied, or was not appropriate for use in the particular case; (e) the opinion relies on an inference or conclusion which has not been properly reached.
When assessing the reliability of expert opinion evidence, the court must have regard to (a) such of the generic factors set out in Part 1 of the Schedule as appear to the court to be relevant; (b) if any factors have been specified in an order made under Part 2 of the Schedule in relation to a particular field, such of those factors as appear to the court to be relevant; (c) anything else which appears to the court to be relevant.
(a) The extent and quality of the data on which the opinion is based, and the validity of the methods by which they were obtained.
(b) If the opinion relies on an inference from any findings, whether the opinion properly explains how safe or unsafe the inference is (whether by reference to statistical significance or in other appropriate terms).
(c) If the opinion relies on the results of the use of any method (for instance, a test, measurement or survey), whether the opinion takes proper account of matters, such as the degree of precision or margin of uncertainty, affecting the accuracy or reliability of those results.
(d) The extent to which any material upon which the opinion is based has been reviewed by others with relevant expertise (for instance, in peer-reviewed publications), and the views of those others on that
material.
(e) The extent to which the opinion is based on material falling outside the expert?s own field of expertise.
(f) The completeness of the information which was available to the expert, and whether the expert took account of all relevant information in arriving at the opinion (including information as to the context of any facts to which the opinion relates).
(g) Whether there is a range of expert opinion on the matter in question; and, if there is, where in the range the opinion lies and whether the expert?s preference for the opinion proffered has been properly explained.
(h) Whether the expert?s methods followed established practice in the field; and, if they did not, whether the reason for the divergence has been properly explained.
The Commission states that the test would not need to be applied routinely or unnecessarily but it would be applied in appropriate cases and it would result in the exclusion of unreliable expert opinion evidence. Under the test, expert opinion evidence would not be admitted unless it was adjudged to be sufficiently reliable to go before a jury. (It is a moot point whether a jury would then be more inclined to accept such evidence since they would probably know that it had passed the judge before they heard it ?).
If a trial is in the Magistrates' Courts, the Commission say that the admissibility must be decided by a District Judge (Magistrates' Courts) who should (according to the Commission) provide a written admissibility ruling, and then the judge should ordinarily try the case. There may be some exceptions to this which will be specified in Criminal Procedure Rules. The Commission add that they - accept that magistrates' courts should have the power to allocate the trial to a bench of lay magistrates, if it is unnecessary for a District Judge to continue with the case."
Other jurisdictions and other material:
"Reliability" tests are not unknown in other jurisdictions. For instance, the Supreme Court of the USA has developed a test (sometimes referred to as "Daubert" from the case of Daubert v Merrell Dow Pharmaceuticals 509 US 579 (1993) though the origins of the rest are older. See also Federal Rules of Evidence (Rule 702). The Daubert test has been criticised as insufficiently effective in criminal cases - see the Law Commission's report for further discussion.
The House of Commons Science and Technology Committee 7th Report of Session 2004-5 "Forensic Science on Trial" and the Labour Government's response to that report.
A leading book in this area is "Expert Evidence: Law and Practice" by Tristram Hodgkinson and Mark James.
See also: the Solicitor's Journal view of the report ..... Government review of Forensic Science Research and Development (Home Office) ..... and Law and Lawyers Forensic Science Service to be wound up
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Law and Rights
Expert Evidence reliability to be tested by Judges - Law Commission Report
The Law Commission has published "Expert Evidence in Criminal Proceedings in England and Wales" (Law Com No. 325 - 21st March 2011). The Commission's Report contains many recommendations relating to the admissibility of expert evidence in criminal proceedings in England and Wales. There is also a Draft Bill - set out at Appendix A of the report (page 144). The Commission has stated: "Too much expert opinion evidence is admitted without adequate scrutiny because no clear test is being applied to determine whether the evidence is sufficiently reliable to be admitted" - see Law Commission for their fuller statement.
- the court must be satisfied that it would provide information which is likely to be outside a judge or jury?s experience and knowledge, and which would give them help they need in arriving at their conclusions
- the witness must be qualified to give the evidence;
- the evidence is not made inadmissible as a result of clause 3 (impartiality)
- In addition, expert opinion evidence is admissible in criminal proceedings only if it is sufficiently reliable to be admitted (see clause 4).
might think that the first three bullet points are obvious. They are included because the Commission wished to put in a single piece of legislation all the relevant law relating to admissibility of this type of evidence. They key new feature is the proposed reliability test which is set out in Clause 4 and Schedule 1 of the Draft Bill.
A reliability test
The decision on reliability would be for the trial judge alone. Under Clause 4, expert opinion evidence is sufficiently reliable if (a) the opinion is soundly based, and (b) the strength of the opinion is warranted having regard to the grounds on which it is based. Certain matters could, in particular, provide a reason for determining that expert opinion evidence is not sufficiently reliable: (a) the opinion is based on a hypothesis which has not been subjected to sufficient scrutiny (including, where appropriate, experimental or other testing), or which has failed to stand up to scrutiny; (b) the opinion is based on an unjustifiable assumption; (c) the opinion is based on flawed data; (d) the opinion relies on an examination, technique, method or process which was not properly carried out or applied, or was not appropriate for use in the particular case; (e) the opinion relies on an inference or conclusion which has not been properly reached.
When assessing the reliability of expert opinion evidence, the court must have regard to (a) such of the generic factors set out in Part 1 of the Schedule as appear to the court to be relevant; (b) if any factors have been specified in an order made under Part 2 of the Schedule in relation to a particular field, such of those factors as appear to the court to be relevant; (c) anything else which appears to the court to be relevant.
Generic Factors set out in the Schedule to the Bill -
(a) The extent and quality of the data on which the opinion is based, and the validity of the methods by which they were obtained.
(b) If the opinion relies on an inference from any findings, whether the opinion properly explains how safe or unsafe the inference is (whether by reference to statistical significance or in other appropriate terms).
(c) If the opinion relies on the results of the use of any method (for instance, a test, measurement or survey), whether the opinion takes proper account of matters, such as the degree of precision or margin of uncertainty, affecting the accuracy or reliability of those results.
(d) The extent to which any material upon which the opinion is based has been reviewed by others with relevant expertise (for instance, in peer-reviewed publications), and the views of those others on that
material.
(e) The extent to which the opinion is based on material falling outside the expert?s own field of expertise.
(f) The completeness of the information which was available to the expert, and whether the expert took account of all relevant information in arriving at the opinion (including information as to the context of any facts to which the opinion relates).
(g) Whether there is a range of expert opinion on the matter in question; and, if there is, where in the range the opinion lies and whether the expert?s preference for the opinion proffered has been properly explained.
(h) Whether the expert?s methods followed established practice in the field; and, if they did not, whether the reason for the divergence has been properly explained.
The Commission states that the test would not need to be applied routinely or unnecessarily but it would be applied in appropriate cases and it would result in the exclusion of unreliable expert opinion evidence. Under the test, expert opinion evidence would not be admitted unless it was adjudged to be sufficiently reliable to go before a jury. (It is a moot point whether a jury would then be more inclined to accept such evidence since they would probably know that it had passed the judge before they heard it ?).
If a trial is in the Magistrates' Courts, the Commission say that the admissibility must be decided by a District Judge (Magistrates' Courts) who should (according to the Commission) provide a written admissibility ruling, and then the judge should ordinarily try the case. There may be some exceptions to this which will be specified in Criminal Procedure Rules. The Commission add that they - accept that magistrates' courts should have the power to allocate the trial to a bench of lay magistrates, if it is unnecessary for a District Judge to continue with the case."
Other jurisdictions and other material:
"Reliability" tests are not unknown in other jurisdictions. For instance, the Supreme Court of the USA has developed a test (sometimes referred to as "Daubert" from the case of Daubert v Merrell Dow Pharmaceuticals 509 US 579 (1993) though the origins of the rest are older. See also Federal Rules of Evidence (Rule 702). The Daubert test has been criticised as insufficiently effective in criminal cases - see the Law Commission's report for further discussion.
The House of Commons Science and Technology Committee 7th Report of Session 2004-5 "Forensic Science on Trial" and the Labour Government's response to that report.
A leading book in this area is "Expert Evidence: Law and Practice" by Tristram Hodgkinson and Mark James.
See also: the Solicitor's Journal view of the report ..... Government review of Forensic Science Research and Development (Home Office) ..... and Law and Lawyers Forensic Science Service to be wound up
- Criminal Law ~ The Law Commission On Insanity And Automatism
Included in recent publications by the Law Commission are: (a) Discussion paper on Insanity and Automatism published 23 July 2013 and (b) Unfitness to Plead consultation responses published 10 April 2013. a) Insanity and Automatism: In July 2012, the...
- Air Accident Investigation Branch Reports - Admissibility In Evidence At Civil Proceedings
In civil aviation, few reports are more respected than those of the Department of Transport's Air Accident Investigation Branch (AAIB). The AAIB undoubtedly seeks to ensure that its investigations are as thorough as possible and that any recommendations...
- A Family Inheritance Wasted On Litigation
The recent case of Hawes v Burgess [2013] EWCA Civ 74 illustrates the high financial cost of litigation relating to wills. The Court of Appeal upheld the trial judge's finding that the deceased's last will, in which the testatrix cut out...
- Dna: Is It Truly The "gold Standard" Of Forensic Techniques?
Updated 25th December 2011 Updated 6th August Some are attributing it to the "silly season" but a debate has broken out about restoration of capital punishment. I have no hesitation in declaring that I am opposed to it. Furthermore, it...
- Expert Witnesses: May We Sue Them?
Expert witnesses appear in many cases. Their evidence may be decisive and, occasionally, it may devastate someone's life. The evidence may turn out to be mistaken. An "expert" witness has to be accepted as such by the court and,...