Dog Law, Dog Expert Witness information.
Meetings between Dog Witness Experts:
Expert evidence which is both accurate and forensically sound
can be daunting for a lay audience, particularly if opposing experts
have points of disagreement. The current position in English law
is examined to show the advantages and problems of pre-trial meetings
between canine (dog) expert witnesses but encompasses al witness
types.
Keywords: Expert evidence, Court Procedure, Digital evidence,
English Criminal Procedure Rules, Admissibility
A persistent problem in criminal trials involving complex technical
evidence is how such material can be fairly presented to a lay
audience while ensuring that prosecutors have the maximum opportunity
to see wrong-doers convicted and the defence equal opportunity
– “parity of arms” - to challenge evidence and
produce alternative explanations. The problem is at its greatest
when experts retained by each side do not or cannot agree.
Existing court procedures do not help: “Many legal rules
and procedures were
ostensibly designed to facilitate disputes about facts. Yet,
certainly at common law, legal processes often seem to provide
smoke-screens to conceal subjective judgements by persons with
an interest in the outcome of proceedings” 1
The rate of change within digital forensics - itself a function
of rates of change in operating systems, hardware, applications
programs and social constructs – exacerbates the difficulties.
There are always new challenges which have to be met via enquiry
and experimentation.
Even highly skilled and experienced experts may find themselves
at any one time ignorant of individual new developments. A related
but increasingly significant problem is the cap on public funding
experienced by prosecution and defence experts alike; full exhaustive
tests to establish a particular point may take longer than courts
will tolerate or be more expensive than the state is prepared
to fund from tax-payers' money. There can be strong pressure simply
to concentrate on the immediate issues in contention before the
court.
1 Andrew Ligertwood, in Innovations in Evidence and Proof, Ed
Roberts & Redmayne, Hart
Publishing, Oxford, 2007
Meetings between Experts /p 2
A possible solution is now formally available in the English
courts via a provision in
Part 33 of the Criminal Procedure Rules 2 . Rule 33(5) says:
33.5 Pre-hearing discussion of expert evidence
(1) This rule applies where more than one party wants to introduce
expert evidence.
(2) The court may direct the experts to –
(a) discuss the expert issues in the proceedings; and
(b) prepare a statement for the court of the matters on which
they agree and disagree,
giving their reasons.
(3) Except for that statement, the content of that discussion
must not be referred to
without the court's permission.
The Rule appeared at the end of 2007 but meetings between experts
had been taking place informally for many years before that, either
voluntarily because the respective legal teams thought a meeting
would be useful or because a judge had suggested or ordered it.
The precise details are a function of specific English criminal
procedure but there are potential lessons for other jurisdictions.
In this article I want to describe some of the advantages and
difficulties associated with such meetings and the necessary framework
within which they must take place.
Some definitions and background.
“Expert” in the way it used by the courts can mean
two different things. The first is the provision of evidence that
is technical in nature. A technician carries out a
procedure, reports on it and produces some exhibits. A typical
example would be the making of a forensic image of a disk including
a description of the precise methodology and verification; at
the end there is the provision of an exhibit in the form of a
disk image. A second example is when the forensic image is examined
and a series of print-outs of files are produced together with
a statement about their locations on disk.
The second sense of “expert evidence ” is evidence
of opinion, which may be tendered by the same technician or by
another witness. Here, and the rules vary between jurisdictions,
the court must first be persuaded that the witness has relevant
expertise and that the opinion to be provided is within the scope
of the witness's expertise but does not trespass into territory
where the court can make up its own mind. Moreover opinion evidence
should never directly address the “ultimate question”
of a defendant's guilt. A typical example might involve a reconstruction
of events and an opinion, based on analysis and experience, leading
to the conclusion that one particular person rather than several
alternatives was responsible for a specific sequence of events.
Another example is where a court is given technical and socio-cultural
background on a particular Internet institution such as chat-rooms,
2 http://www.justice.gov.uk/criminal/procrules_fin/contents/rules/part_33.htm
Meetings between Experts /p 3
social networks, e-commerce protocols, so that it can understand
the circumstances of an alleged offence.
In the United States, for example, this second type of expert
evidence is dealt with under Federal Rules of Evidence 702 3 :
“If scientific, technical, or other specialized knowledge
will assist the
trier of fact to understand the evidence or to determine a fact
in issue, a
witness qualified as an expert by knowledge, skill, experience,
training, or
education, may testify thereto in the form of an opinion or otherwise,
if
(1) the testimony is based upon sufficient facts or data, (2)
the testimony
is the product of reliable principles and methods, and (3) the
witness has
applied the principles and methods reliably to the facts of the
case.”
The apparent alternatives
Judicial systems seem to offer a number of alternatives to handling
disputed expert evidence 4 :
Let the court decide This is the simplest form, particularly
in the common law jurisdictions where the procedure is adversarial
5 . Expert witnesses take their turn among all the other witnesses
that each side decides to offer. The Prosecution expert may appear
quite late in the prosecution case. S/he is examined, cross-examined
and re-examined. The prosecution case continues and the defence
case opens. Several days, sometimes weeks and months later, the
defence expert goes into the witness box. S/he too is examined,
cross-examined and re-examined.
The court, and especially a lay jury, are expected to retain
in their minds the earlier explanations and assertions of the
prosecution expert and compare them with that of the defence expert.
The defence expert witness finishes and is followed by other
witnesses. Still later the respective lawyers make their closing
speeches, referring among other things, to the expert evidence.
The judge then sums up, again referring to the expert evidence
and describing the law as it affects the trial as a whole.
The jury, assuming there is one, must finally retire and decide.
The danger here is that the jury has never had a clear technical
explanation of the technologies and science involved; it has heard
competing views presented in circumstances which makes learning
and understanding very difficult. There is little assistance in
seeing how far the respective experts agree. There may be not
much in the way of background to some of the technologies –
what is IRC or P2P? What is an
Internet browser cache? What is a botnet?
3 http://www.law.cornell.edu/rules/fre/rules.htm#Rule701 provides
a convenient annotated guide
4 A lengthy discussion of this and other issues relevant to this
article appears in the UK Criminal Court Review conducted by Auld,
LJ and published in 2001: http://www.criminal-courts-review.org.uk/
. Chapter 11 is particularly helpful
5 In the adversarial criminal procedure police investigate, a
prosecuting authority determines precise
charges, and the judge acts as a chairman of proceedings and
enunciates the law. The jury, if there is one, decides on facts
as presented by opposing advocates and their witnesses. In the
inquisitorial
criminal procedure the investigation is supervised from an early
stage by a judge who also frames the charges; the trial is presided
over by a different judge.
Meetings between Experts /p 4
It is small wonder that many fear that the basis of arbitrating
between different expert evidence is not the intrinsic merit but
the theatrical experience – do members of the jury “trust”
one expert over another on the basis of a recital of qualifications,
or because one looks avuncular and professorial and another is
a casting director's idea of a geek and who wears an off-putting
T-shirt? Or is it the voice, manner and self-confidence of an
expert which becomes the determinant?
But the principle of the adversarial system is retained.
The single expert In this situation the court appoints an expert.
The expert may be called an “assessor”; they may even
sit along side the judge as opposed to be called to testify from
the witness box. This was a solution suggested in relation to
trials involving complex fraud by the UK Roskill Committee in
1986, though it was heavily criticised at the time and subsequently
6
There is one great advantage; that a lay jury does not have to
bother itself with
“difficult” material. But then great reliance is
put upon who-ever the court-appointed expert is. How is s/he selected
in the first place? What opportunities exist to challenge their
findings?
There is a variant: the single joint expert, or SJE. Here the
parties agree on the expert and also on his/her precise instructions.
Usually the agreement is then supported and enforced by the court.
This can work quite well in civil cases where the Claimant and
Defendant have equal status and are under an obligation to restrict,
so far as possible, the scope of their dispute 7 . In England
and Wales the precise arrangements appear in the Civil Procedure
Rule 35.8 8 and with greater detail in a Practice Direction 9
.
One criticism of the SJE is that one can end up with, not the
single expert the system advocates, not the two – one per
side – that is seen in conventional disputes, but three:
the court appointed SJE and each side retains an expert in order
to “manage” the SJE.
In criminal cases, though, what may be at issue is the reputation
and liberty of an individual. There is far less possibility for
agreement between prosecution and defence lawyers as to limiting
the scope of the dispute: the prosecution makes the best case
it can on the evidence it has acquired and the defence disputes
it as far as it is able.
The English Criminal Procedure Rules do allow for a SJE –
CPR 33.7 and 33.8 10 but
this is limited to the circumstances in which there are several
co-defendants. The aim here is to avoid unnecessary duplication
of effort in the presentation of the defence case, not to have
a SJE who settles a point in contention between the prosecution
and the defence.
Judicial arbitration on expert evidence Here, to a greater or
lesser extent, the task of evaluating experts and expert evidence
is devolved to a judge.
6 http://www.dca.gov.uk/criminal/auldcom/jud/jud10.htm ; http://www.criminal-courtsreview.
org.uk/ccr-11.htm 7 In English law the Civil Procedure Rules
describes the “overriding objective” as dealing with
a case to save expense and to deal with the issues in a manner
proportionate to the sums involved:
http://www.justice.gov.uk/civil/procrules_fin/contents/parts/part01.htm
8 http://www.justice.gov.uk/civil/procrules_fin/contents/parts/part35.htm
9 http://www.justice.gov.uk/civil/procrules_fin/contents/practice_directions/pd_part35.htm
10 http://www.justice.gov.uk/criminal/procrules_fin/contents/rules/part_33.htm#rule33_7
Meetings between Experts /p 5
In the code-based law of Europe and those jurisdictions borrowing
from it, the procedure is inquisitorial, with a supervising or
investigating magistrate – judge d'instruction – directing
the activities of the police and framing the charges. These judges
will look at the expert evidence and test it for “relevance”
and “fairness”
Their scope for discretion is increased in those jurisdictions
where there is an “inclusionary” as opposed to “exclusionary”
doctrine of admissibility. In the former, almost any item of evidence
can be admitted for consideration unless there is a rule forbidding
it. Examples include, to varying degrees, France, Portugal, Belgium
and Italy. Under the exclusionary doctrine all evidence is excluded
unless there is a positive rule to allow it in. Dutch and German
law provide lists of allowable evidence. There is an argument
for saying that because the investigating judge can look at expert
evidence freed from the formal procedures of a trial they can
test it more thoroughly. On the other hand, much will then depend
on the knowledge and ability of the investigating judge. There
does not seem to be much scope for testing by a defence expert
until quite late in a final trial. In the United States there
is sort-of half-way house for novel scientific evidence under
the Frye / Daubert / Khuomo Tire Rules 11 . Here the judge has
a voir dire or trialbefore- the-trial to consider whether a strand
of scientific or technical evidence is “generally accepted”.
The aim is to prevent quack science being placed before a jury.
If the judge decides that the evidence meets the four main “Daubert”
tests;
Has the theory or technique been reliably tested?
Has the theory or technique been subject to peer review?
What are the theories or techniques known or potential error rates?
Has the theory or technique been generally accepted as a standard
in its
scientific community?then the evidence can be admitted for consideration
in the main trial. But these tests apply to the techniques deployed,
not to the credibility of an expert and not to any conclusions
that might be drawn from them. 12
The English Procedure
The English way of handling expert evidence has to be understood
within the broader context of criminal justice procedure and in
particular those features which are different from those in similar
jurisdictions. These are: an explicit statement of where the expert's
ultimate duty lies, the regime which defines Prosecution and Defence
duties of disclose, and the role and function of pre-trial Case
Management hearings
Expert's Duty
11 Frye v. United States, 293 F. 1013 (D.C. Cir. 1923); Daubert
v Merrell Dow Pharmaceuticals 509
U.S. 579 (1993); Kumho Tire Co., Ltd. v. Carmichael , 526 U.S.
137
12 Christopher V Marsico; COMPUTER EVIDENCE V. DAUBERT: THE COMING
CONFLICT; CERIAS Tech
Report 2005-17; Rogers, M. Computer Forensics: Science or fad.
Security Wire Digest , Vol 5. No.
55,
Meetings between Experts /p 6
Under English law the over-riding duty of an expert witness is
to the court:
33.2 Expert's duty to the court.
(1) An expert must help the court to achieve the overriding objective
by giving objective, unbiased opinion on matters within his expertise.
(2) This duty overrides any obligation to the person from whom
he receives
instructions or by whom he is paid.
(3) This duty includes an obligation to inform all parties and
the court if the expert's opinion changes from that contained
in a report served as evidence or given in a statement 33.3 Content
of expert's report
(1) An expert's report must – ….
(i) contain a statement that the expert understands his duty
to the court, and has complied and will continue to comply with
that duty; and
(j) contain the same declaration of truth as a witness statement.
The expert witness is thus not “on the team” of either
the prosecution or the defence.
Disclosure
English law is also unusual in the way in which it handles disclosure,
the prosecution have an obligation to make the defence aware of
material it has collected during the course of an investigation
and which might affect the outcome of a trial even though that
material is not being presented as evidence. (The US term is “discovery”).
Until 1997, English law was similar to that of most other “common
law” countries: the defence could make demands of the prosecution
for “unused” material against a relevancy test 13
.
In 1997 the Criminal Procedure and Investigation Act, 1996, came
into force; it has since been modified by a further Act in 2003.
It places on prosecutors the obligation to disclose to the defence
“unused material” which is “relevant”.
This is defined in the Code of Practice as anything that appears
to an investigator, or the officer in charge of an investigation
or the disclosure officer to have some bearing on any offence
under investigation or any person being investigated or on the
surrounding circumstances unless it is incapable of having any
impact on the case 14 .
But the defence have obligations as well: they must produce a
Defence Case
Statement which sets out the main limbs of their argument, for
example, that facts are disputed, that there is an alibi, that
the defendant was acting under duress, and so on.
It must also indicate if there are to be any legal arguments,
such as admissibility, abuse of process, or interpretation and
application of law. The prosecutor is required to consider the
Defence Case Statement, among other things, to see if he is holding
any material which now looks relevant to the defence. The main
penalties faced by the defence for not producing a Case Statement,
or one with sufficient detail, are that 13 R v Keane (1994) 99
Cr. App.R 1 summarised the earlier common law precedents. 14 http://www.cps.gov.uk/legal/section20/chapter_a.html#012
Meetings between Experts /p 7
they won't then be able to challenge the Prosecution that there
is still further material which ought be disclosed, while at trial
“adverse inferences” may be drawn. (Including that
the defendant was given an opportunity to give the police a chance
to decide that they had been mistaken, or that a line of defence
has been produced at the very last moment).
In the United States there is a general obligation on the prosecution
not to withhold evidence which is either material to guilt or
punishment. Brady v. Maryland , 373 U.S. 83 ( 1963 ). In effect
failure to disclose is regarded as violation of due process and
the equal protection of the laws under the Fourteenth Amendment
to the US constitution. As with many features of US law, precise
details vary between individual States.
Case Management Hearings
English courts are placing increasing importance on pre-trial
hearings in which
opposing lawyers and the judge discuss and settle issues about
the management of the trial: How long is it expected to last?
How many witness will be produced and how long will each be examined?
Will there be a need for special equipment in court – such
as a computer or video player? Are there young defendants whose
identity must be guarded? Will some witness testify by video link?
Will there be expert witnesses and when will their reports be
available? Are there any admissibility and legal issues?
Is there scope for agreement between prosecution and defence
on certain facts? A timetable is set by which both sides are required
to produce papers to each other.
The current term for this is “Plea and Case Management
Hearing”, or PCMH.
Both the Disclosure regime and the PCMH requirement came from
reforms which in turn had emerged from reports and commissions
which had concluded that all was not well with English criminal
justice procedures 15 . In the case of disclosure there were concerns
about miscarriages of justice because the police had withheld
key information from the defence – these have not entirely
disappeared even now 16 . But there were also complaints from
the police that defence lawyers had been engaging in “fishing
expeditions”, asking for huge amounts of information in
the vague hope that something useful – or embarrassing to
the police might turn up.
Case Management hearings have become steadily more important
because of the need to discipline the trial process. The movie
and TV screenwriter thrives on witnesses and essential evidence
discovered at the last minute; in practice the most efficient
way of delivering justice is where both sides and the judge are
entirely clear before the trial starts about what will be said
before a jury. That way, witnesses can be called in an order which
explains the events in the most logical way and there are a minimum
of situations where the jury has to be sent out while opposing
lawyers argue a point of law.
But it is also fair to say the PCMHs are still not working as
well as they might: the mechanics of the way in which public funding
is granted often has the result that 15 Runciman Cmnd 2263 (HMSO
1993); Auld http://www.criminal-courts-review.org.uk/
16 http://www.innocent.org.uk/misc/disclosure.html
Meetings between Experts /p 8
PCMHs are attended, not by the leading advocates who will appear
at trial, but their juniors. As a result critical issues are sometimes
missed. Expert and technical witnesses, who might be able to make
a significant contribution to how specialist evidence will be
presented, are almost never in attendance. 17 And the success
of a PCMH also depends on the skill of the judge; in some complex
cases, where defendants have been held in prison until trial,
judges have pressed for an early trial start-date and said that
evidence can be served while the trial is in progress. 18
Expert Report Format
The Criminal Procedure Rules set out what is expected in a Report
19 :
33.3 Content of expert's report:
(1) An expert's report must –
(a) give details of the expert's qualifications, relevant experience
and
accreditation;
(b) give details of any literature or other information which
the expert has relied on in making the report;
(c) contain a statement setting out the substance of all facts
given to the expert
which are material to the opinions expressed in the report or
upon which those opinions are based;
(d) make clear which of the facts stated in the report are within
the expert's own knowledge;
(e) say who carried out any examination, measurement, test or
experiment which the expert has used for the report and –
(i) give the qualifications, relevant experience and accreditation
of that person,
(ii) say whether or not the examination, measurement, test or
experiment was carried out under the expert's supervision, and
(iii) summarise the findings on which the expert relies;
(f) where there is a range of opinion on the matters dealt with
in the report –
(i) summarise the range of opinion, and
(ii) give reasons for his own opinion;
(g) if the expert is not able to give his opinion without qualification,
state the
qualification;
(h) contain a summary of the conclusions reached;
(i) contain a statement that the expert understands his duty
to the court, and has complied and will continue to comply with
that duty; and
(j) contain the same declaration of truth as a witness statement.
17 But it does happen sometimes
18 eg Jubilee Line fraud, Operation Blossom trial, currently
two of the most expensive ever UK trials
19 http://www.justice.gov.uk/criminal/procrules_fin/contents/rules/part_33.htm#rule33_3
Meetings between Experts /p 9
One weakness of the Rule is that it doesn't address a constant
dilemma of anyone
whoever writes an expert forensic report: to whom is a witness
statement actually
addressed? The court or another expert?
The problem is this: good scientific forensic practice requires
the qualities of accuracy, completeness, transparency and testability.
But that can lead to levels of detail that lay members of the
court – a judge, a jury if present, may find intimidating
and unhelpful. What assumptions should be made in terms of levels
of knowledge? How far and when are “accurate ethical simplifications”
justified?
But there may also be circumstances where an opposing expert
needs the detail in order to be convinced of the rightness of
the methodology and conclusions being tendered in a witness statement.
Meetings between Experts
This is what Sir Robin Auld said in his Report in 1999: 145 As
to pre-trial meetings between experts, this occasionally takes
place on an informal basis with the agreement of both parties,
but I believe it to be the exception rather than the rule. If
the views expressed in the Review are representative, the reluctance
to arrange such meetings comes mainly from the defence, not the
prosecution or the expert witnesses themselves, both of whom urge
it. Subject to proper safeguards of confidentiality as to undisclosable
information on both sides, I strongly encourage it. It is obviously
of great assistance to the court in the simplification of the
expert evidence over-all. And it can give no improper advantage
to either party if they can discuss and identify in advance the
extent of the likely issue between them when the matter goes to
court. It is of particular importance where one side is proposing
to use information technology for the presentation of some of
its evidence, since there will need to be discussion of the system
to be used, as well as of content of the evidence. 20
This recommendation lead to the creation of the Criminal Procedure
Rule 33.5, quoted at the beginning of this article. Perhaps the
three most important features, other than the overarching one
that such meetings can take place are
The judge can order a meeting to take place irrespective of the
wishes of
the prosecution and defence lawyers The output is an agreed statement
indicating points of agreement disagreement No reference can be
made in court to any discussions between the experts other than
that which is in the agreed statement 20 h ttp://www.criminal-courts-review.org.uk/ccr-11.htm
Meetings between Experts /p 10
Examples
The following are examples within the writer's own experience,
largely gathered from the “informal” situation that
existed prior to the arrival of CPR 33.5:
Agreement on how to explain a particular technology In a case
where “place of publication” was an issue and a web-server
was located overseas outside the jurisdiction of the court, there
was an agreed statement on how web-site authoring, web-server
publication, and web-site reception worked. The judge was then
able to apply the law; the matter went to appeal, where the original
judge's findings were accepted.
• Agreement on a demonstration IRC - Internet Relay Chat
had been used in a covert form by a group of file-swapping paedophiles.
There was an agreed “live” demonstration in court
of what IRC looked like from the perspective of the ordinary user.
• Agreement on glossary of terms Such agreements are now
used in almost all hi-tech cases of any complexity
• Agreement on specific aspects of evidence It is often
quite easy to get agreement on such issues as:
That there is no dispute that a hard-disk was preserved and imaged
correctly
That certain file or fragments are located on a hard-disk at
specific disk location and with associated date-and-time stamps
Such agreements can speed the trial process and the respective
lawyers can focus the court's attention on areas where there is
real dispute
• Defence seeking clarification of technical infrastructure
at victim's premises.
It is often difficult to understand how a complex computer system
operates simply from documentation and paper-based description.
The defence expert may need to develop an understanding quite
quickly. Examples include: a site visit to a computer manufacturing
company which had suffered an internal fraud; an examination of
the facilities available at branches of the UK Post Office where
there had been clerical frauds, a site visit to an insurance company
which had been email-bombed
• Prosecution demonstration of methodology and/or tool
to show validity /Mutual testing of artefacts to show there is
a valid forensic argument.
It is still the case that many significant discoveries about
the forensic value of OS and application artefacts emerge during
real investigations, as opposed to being the product of academic
research. In those circumstances there may be no peer-reviewed
article on whose authority the parties can rely, though an article
might appear later. Examples include: the extent to which useful
information can be found in thumbs.db files, the linking of registry
items about USB devices to actual devices material to the case,
the ways in which date/time stamps are recorded in Restore Points.
• Agreement on chronology of events One of the commonest
techniques of investigation, or of the repudiation of an allegation
– is the chronology of events. Indeed this technique is
fundamental to any “whose fingers on the Meetings between
Experts /p 11 keyboard at the relevant time” argument. Using
modern forensic software it is trivial to arrange files in date
order. But interpretation is much more complex: which files do
you regard as significant? Are you sure about the circumstances
in which a file was “created”, or “last written”
or “last accessed”? How do you establish a date of
deletion? How can you reconstruct Internet browsing activities
where some important pages almost certainly would have had a no-cache
flag?
Sometimes chronologies have to be built up from several different
strands of evidence, computer hard-disks, web-access logs, anti-virus
logs, cellphone usage logs, diaries. Recent examples have included
an internet defamation and several accusations of downloading
of indecent images of children where several people had access
to the computer upon which the images were found.
• Agreement on chronology of successive drafts of a document
. In one case where over a period of several days a police officer
compiled statement to be signed by a witness. Later the witness
claimed that the statement as signed by him was not the true final
version. A chronology of drafts was compiled from recovered temporary
files and file fragments and associated date/time stamps were
married with other sources of timed evidence. After a short meeting
the opposing experts were able to agree.
• Method of decrypting In one case a prosecution expert
announced via a witness statement that he had successfully decrypted
an encrypted file. But he failed to refer to any methodology,
any identification of the encryption algorithm and did not provide
the key he said he had discovered. The matter was resolved in
an expert-to-expert meeting.
• Examination of Java in web-pages to test for “pop-up”
defence The unexpected, not-sought, pop-up windows defence occurs
with depressing frequency in cases involving the downloading of
indecent images of children. Although many of these claims are
undeserving it is possible to examine date/time stamps on pages
adjacent to the ones containing the offending material and then
examine any java code. This is precisely the sort of evidence
that is difficult for lay juries but on which experts ought to
be able to agree.
Problems and Limitations
Although there are many benefits to expert-to-expert meetings
within the English law framework a number of dangers and problems
are being identified.
• Setting of parameters of meetings Faced with conflicting
expert reports, some judges are tempted to leave the details of
what is discussed at an expertto- expert meeting to the experts.
The meeting then starts without a clear agenda. This can sometimes
have an unfortunate effect. Inexperienced experts may exceed their
remits. Opposing lawyers may try to influence the meetings, either
extending or restricting the terms, depending on what they think
the outcome may be. Experts may need to be robust to ensure that
their duty to the court is not compromised. Generally speaking,
if an expert believes the parameters are unclear, he may have
to force those instructing and if necessary the trial judge to
set the agenda.
Meetings between Experts /p 12
• Experts can usurp the role of the jury The principle
is quite clear: experts are there to assist the court and jurors
in just those areas where the layperson is unlikely to be able
to make up his/her mind. But where nearly all the evidence is
technical and nearly all the action takes place within computers,
it may be extremely difficult for experts to know precisely the
point at which they should stop – and for judges to know
when to intervene
• Lack of Training Courses At the moment training for expert
witnesses tends to concentrate either on the particular expertise
(eg hard-disk examination) or on court requirements – writing
reports and statements in the approved manner and how to give
oral evidence. There appears to be no training available in how
to manage the expert-to-expert meeting. Another critical requirement
in training is to assist the expert in managing his relationships
with “those instructing” when there is an over-riding
duty to the court – we consider this below.
• Funding The vast majority of criminal cases in England
are publicly funded and that means that an independent body, the
Legal Service Commission, has to agree that a particular activity
should be supported, and to what extent.
Decisions are usually made by civil servants and they may not
understand what is involved in an expert-to-expert meeting and
what level of preparation is required. Or they may take a very
long time to reach a decision, by which point the trial start
date is imminent.
• Opposing experts may be too friendly Quite often experts
will know each other from previous instructions and may also have
met on other occasions. In effect, in a trial, the person to whom
the expert most closely relates is his/her opposite number. The
danger here is that they do not test each other sufficiently.
There is a corollary: some times experts form a mutual dislike
and then their aim can be to show up the supposed deficiencies
of their opponent rather than serve the court.
• A conversation between an expert hired by the defence
and one hired by the prosecution may result in “too much”
of the defence case being released prematurely Although the trend
in the English criminal courts is towards greater clarity of each
side's arguments before the trial begins, the defence can still
make decisions about what and when to reveal. A defence expert
may be privy to other aspects of the defence case and may inadvertently
reveal privileged and other information. There is a formal safeguard
in the rule that no reference can be made in court to any discussions
between the experts other than that which is in the agreed statement
but this may not stop informal (and very damaging) leakage.
• Problems for prosecution experts Prosecution experts
have usually played some part in the investigation that lead to
the charges against the defendant being framed. Indeed they may
be law enforcement officers, civilians employed by a law enforcement
agency, or be in private practice but regularly receiving contracts
from law enforcement agencies. They are the colleagues of the
investigators. But they also owe duties to the court. If they
are to give evidence the over-riding duty is then to the court,
not to colleagues and Meetings between Experts /p 13 employers.
In English law, they also have a duty to record their activities
accurately and to respond to a prosecutor's demands that anything
adverse to the prosecution case will have to be disclosed to the
defence. When giving evidence, it is not an option for a prosecution
expert to be helpfully selective in what he says.
• Problems for defence lawyers There are a set of related
problems, not directly connected to expert-to-expert meetings,
but which apply to defence experts. Since the expert is not “on
the defence team” but owes a duty to the court, defence
lawyers will want to exercise some control over investigations
carried out by defence-instructed experts. In particular if a
defence advocate suspects that his client is not telling him the
truth he will not want to be put in a position where the extent
of the lie is forcibly drawn to his attention as a result of investigations
by his own expert. If that happens, he will be bound either to
confront the client, or “return the brief” (resign).
But constraining the activities of the defence expert may also
mean that evidence that could help the defendant remains hidden.
In any event making decisions in this area implies that the advocate
has a great deal of knowledge about digital forensics.
Usually the only way round this is for the defence advocate to
warn the client that an expert is being instructed, that it may
not be possible to control the situation if adverse evidence is
found and to be quite sure that the client is happy for the investigation
to go ahead. It is quite common for a defence expert to make a
finding which is not “helpful” to a defendant but
not to the point at which the advocate feels he has been lied
to.
The usual route then is not to “call” the expert
to give evidence but to use him to assist in building a general
understanding of the case and to develop a cross-examination strategy
for the prosecution's expert.
In addition there is no doubt that, faced with an unpromising
case, a defence advocate may prefer not to be too helpful in assisting
a jury to understand a case. The advocate may want to play the
“reasonable doubt” card – “if you don't
understand you shouldn't convict”
Conclusions
The formal English procedure for Expert-to-Expert meetings is
still very new. Some of the problems indicated above are likely
to be solved by a combination of training (for experts, lawyers
and judges) and experience.
There is no such thing as a prefect criminal justice system and
there is always the temptation for professionals in one jurisdiction
to look enviously at the best features of procedures in other
jurisdictions.
But the problems of placing complex technical evidence in front
of a court full of laymen whilst preserving overall fairness and
parity of arms won't go away. The precise methods currently evolving
in the English court, though, may provide some lessons for other
jurisdictions. In particular some formalisation of the ways in
which experts can meet prior to trial must be a good idea.