The role of the expert witness in the adversarial legal system

The role of the expert witness in the
adversarial legal system

Roy G Beran*

So often we hear the legal profession berate expert witnesses as “hired guns”
whose bias is for sale. While this may be relevant to a small minority of
“experts”, the majority do their job with integrity and in an ethical fashion. An
advocate for a proposition will not call a witness to support a claim if it is clear
that the witness holds an opposing view. It follows that the bias emanates
from the lawyer, not the witness. A witness without a formed view cannot truly
claim to be an expert, as the expert should have sufficient knowledge to form
an opinion. Once that opinion has been expressed and justified, the lawyer
will select the most persuasive and cogently constructed opinion with which
to convince the court. The expert witness must commence the assessment
without bias or favour; must collect her or his history and examination of the
relevant material; evaluate all the facts and evidence provided for scrutiny;
seek additional material where there appears to be a deficiency; and draw on
all of these data to formulate an opinion in response to questions posed by
the instructing lawyer. The expert need not support or refute the stance
proposed by the lawyer but the lawyer will only use those opinions favourable
to the lawyer’s case and hold the remainder as privileged where even that
option prevails. It follows that the role of the expert is to provide a
well-prepared analysis; it is the lawyer who is paid to be biased.

INTRODUCTION

All too often expert witnesses are described as “hired guns”1 whose “expertise” is sold to the highest
bidder. They are considered biased2 and a blight on the legal process which relies upon their
contribution to assist the court.3 Such contribution is considered depreciated,4 thereby casting
aspersions upon all expert witnesses who are tainted by the acts of a few.

Experts provide the court with the advantage of technical knowledge that is not widely available
to a lay community.5 It is important that such knowledge be provided on the basis that it is not tailored
to meet the needs of one, or other, side6 within the adversarial system.

* MD, FRACP, FRCP, FACLM, B Leg S, MHL, FFFLM (RCP) Hon, FRACGP; Conjoint Associate Professor, University of
New South Wales; Professor, Griffith University; President, Australian College of Legal Medicine; Secretary General, World
Association for Medical Law.

Correspondence to: Suite 5, Level 6, 12 Thomas Street, Chatswood, NSW 2067, Australia.

1 Andrew LB, “The Ethical Medical Expert Witness” (2003) 89(3) Journal of Medical Licensure and Discipline 125; Cooper J
and Neuhaus IM, “The ‘Hired Gun’ Effect: Assessing the Effect of Pay, Frequency of Testifying, and Credentials on the
Perception of Expert Testimony” (2000) 24 Law & Hum Behav 149; Commons ML, Miller PM and Gutheil TG, “Expert
Witness Perceptions of Bias in Experts” (2004) 32 J Am Acad Psychiatry Law 70; Feld AD and Caret WD, “Expert Witness
Malfeasance: How Should Specialty Societies Respond?” (2005) 100(5) American Journal of Gastroenterology 991;
Anderson JL, Cheitlin MD, Goldstein LB and Grant AO, “Task Force 5: Expert Testimony and Opinions” (2004) 44(8) Journal
of the American College of Cardiology 1747.

2 Commons, Miller and Gutheil, n 1; Anderson et al, n 1; Sattar SP, Pinals DA and Gutheil TG, “Countering
Countertransference: A Forensic Trainee’s Dilemma” (2002) 30 J Am Acad Psychiatry Law 675; Ryan M, “The Adversarial
Court System and the Expert Medical Witness: ‘The Truth, the Whole Truth and Nothing But the Truth?’” (2003) 15(3)
Emergency Medicine 283; Sperling HD, “Expert Evidence: The Problem of Bias and Other Things” (2000) 4(4) Judicial Review
347; Freckelton I, Reddy P and Selby H, Judicial Perspectives on Expert Evidence (AIJA, Melbourne, 1999).

3 Tjiong RTT, “Reforming the Law on Expert Evidence” (1998) 168 MJA 53; Butler-Sloss E and Hall A, “Expert Witnesses,
Courts and the Law” (2002) 95 R Soc Med 431.

4 Cooper and Neuhaus, n 1.

5 Anderson et al, n 1; Australian Medical Association, Guidelines for Doctors Acting as Expert Witnesses (1997),

(2009) 17 JLM 133 133

Beran

Having accepted that the special skills of the expert should not be used for the sole purpose of
underscoring the advocate’s case,7 this does not deny the lawyer the right to use such opinion strictly
for that purpose.8

The apparent paradox within this statement is countered by the fact that the opinion proffered by
the expert should not be artificially manipulated to satisfy the lawyer.9 If it meets the lawyer’s
expectations, then there is no barrier to prevent the lawyer from using it most forcefully to substantiate
the case being made. Most expert witnesses provide their opinions with due recognition of their
responsibility to the court,10 acknowledging the propriety of their obligations11 and doing their job in
an ethical fashion.12

It is axiomatic that the lawyer will not bring into evidence the opinions of an expert if the
conclusions draw by that expert directly conflict with the proposition being espoused by the lawyer.13
Conversely, as already stated, the lawyer will draw heavily from those opinions which lend credence
to the case being asserted. It follows that the bias being projected upon the expert witness is
promulgated from the lawyer’s judicious selection either of a specific expert known to have an
established perspective (as a matter of common knowledge)14 or by selecting only those opinions
favourable to the particular outcome in the case.15

If it be known that in certain circumstances a specific expert has openly stated, and substantiated,
a specific opinion, and that opinion accords with the needs of the lawyer, that does not equate to that
expert being a “gun for hire”. Each expert will have an opinion and often that expert will be known to
hold a particular view within the context of comparable scenarios. As it is the duty of the lawyer to
best represent the case of the client, it is logical for the lawyer to employ an expert known to be
sympathetic to that view, recognising that the opinion held will enhance a given case. So long as that
expert sincerely ascribes to the view for valid reasons, then it is inappropriate to label that expert a
“hired gun”.

What follows is an analysis of the role of the expert witness within the adversarial legal system.

RELATIONSHIP OF LAWYER AND EXPERT

The lawyer will select the expert to be used in a case16 unless that expert is selected by the court.17
Such selection will be based on a preconceived concept of the views of the expert and on the need for

http://www.ama.com.au/web.nsf/doc/SHED-5FTUTX viewed 15 April 2008; Weinstein J, “Expert Witness Testimony. A Trial
Judge’s Perspective” (1999) 17(2) Neurologic Clinics 355; Berlin L, “On Being an Expert Witness” (1997) 168 AJR 607;
DiMitto JW, “The Geriatric Nurse as Witness; Tips for Effective Testimony” (2002) 24(1) Geriatric Nursing 46; Abadee AR,
“The Expert Witness in the New Millennium”, General Surgeons Australia 2nd Annual Scientific Meeting, Sydney, 2 September
2000, http://www.lawlink.nsw.gov.au/lawlink/supreme_court/ll_sc.nsf/pages/SCO_speech_abadee_020900 viewed 16 April
2008; Freckelton I and Selby H, Expert Evidence: Law, Practice, Procedure and Advocacy (4th ed, Lawbook Co, Sydney,
2009).

6 Ryan, n 2; Abadee, n 5; James SH and Nordby JJ, Forensic Science: An Introduction to Scientific and Investigative Techniques
(2nd ed, CRC Press, Boca Raton, Fla, 2005) p 158.

7 Australian Medical Association, n 5.

8 McHenry CR, Biffl WL, Chapman WC and Spain DA, “Expert Witness Testimony: The Problem and Recommendations for
Oversight and Reform” (2005) 137(3) Surgery 274.

9 Stowe H, “Preparing Expert Witnesses: A Search for Ethical Boundaries” (Summer 2006/2007) Bar News 44.

10 Berlin, n 5.

11 Gould JW, Conducting Scientifically Crafted Child Custody Evaluations (Sage Publications, Thousand Oaks, 1998) p 35.

12 Gould, n 11, p 35.

13 Sperling, n 2; Stowe, n 9.

14 Sperling, n 2; Stowe, n 9.

15 Sperling, n 2; Stowe, n 9.

16 New South Wales Law Reform Commission, Expert Witnesses, Report 109, “App E: Joint Expert Witnesses and
Court-appointed Expert Witnesses” (2005a), http://www.lawlink.nsw.gov.au/lawlink/lrc/ll_lrc.nsf/pages/LRC_r109appE viewed
15 April 2008; New South Wales Law Reform Commission, Expert Witnesses, Report 109, “The Uniform Civil Procedure Rules
2005” (2005b), http://www.lawlink.nsw.gov.au/lawlink/lrc/ll_lrc.nsf/pages/LRC_r109chp03#H3 viewed 15 April 2008

134 (2009) 17 JLM 133

The role of the expert witness in the adversarial legal system

an evaluation of the validity of a case. The selection will take into account the knowledge, standing
and experience of the expert18 and the need for the expert to command sufficient presence and respect
to counter any opposing expert.19

The lawyer will provide a letter of introduction outlining any necessary assumptions upon which
an opinion should be based.20 Also included will be the questions to which the expert should provide
answers,21 and reports necessary for the expert to fully evaluate the case.22 Such reports may include
medical records and correspondence from other doctors (in a case of a medical nature) and any
available opinions formed by others.23

The lawyer will outline the case and provide transcripts of the necessary codes of conduct which
the expert will be expected to acknowledge and accept.24 The lawyer will further provide assurance
that the fees of the expert will be guaranteed.25

In return, the expert will agree to examine the client, make an independent assessment, review all
additional documentation and provide an opinion based upon the available information and in
accordance with the stipulated code of conduct for an agreed fee.26

Inherent in this agreement is an obligation for the expert to form and proffer an opinion based on
all the available materials.27 The expert will be expected to justify that opinion and be prepared to
validate such justification under cross-examination by the opposing team of lawyers.28

The expert will also provide the lawyer with sufficient documentation of her or his standing and
experience, in the form of a modified curriculum vitae, to authenticate any claim of expertise.29

CONDUCT OF THE EXPERT WHEN PREPARING A REPORT

The expert should act as an independent agent30 rather than appearing to be a representative of the
lawyer. As such, the expert should attest to such independence as part of any prepared report.

Each expert will adopt a different formula or structure when preparing a report but there are some
minimum criteria which need to be addressed. The report must respect an unbiased approach and
should include a statement to the effect that the expert had completed the report with the inclusion of
an independent history and examination which confirms a lack of influence from other sources.31
Where additional information has been provided, it must be analysed to determine its relevance to and

17 New South Wales Law Reform Commission, n 16 (2005a); New South Wales Law Reform Commission, n 16 (2005b).

18 Stowe, n 9; Samuels G, “Medical Truth and Legal Proof: Changing Expectations of the Expert Witness” (1998) 168 MJA 84.

19 Adshead G, “Evidence-based Medicine and Medicine-based Evidence: The Expert Witness in Cases of Factitious Disorder by
Proxy” (2005) 33(1) J Am Acad Psychiatry Law 99.

20 Gore EH, Selecting an Expert Witness. Risk Management (September 2006), http://www.findarticles.com/p/articles/mi_
qa5332/is_200609/ai_n21398004 viewed 15 April 2008; Notley RG, “The Medical Expert Witness” (2000) 86 British Journal
of Urology International 294.

21 Gore, n 20; Notley, n 20.

22 Gore, n 20; Notley, n 20.

23 Notley, n 20.

24 New South Wales Law Reform Commission, n 16 (2005a).

25 Abadee, n 5; Notley, n 20.

26 Notley, n 20; Blau TH, The Psychologist as Expert Witness (2nd ed, John Wiley & Sons, New York, 2001) pp 37-41.

27 Muroff JA, “Taming the Expert: Standards and Implications of Radiologist Expert Witness Testimony” (2005) 2
J Am Coll Radiol 418.

28 Muroff, n 27.

29 Pentony P, “Medical Expert Opinion Evidence” (August 2005) 2(4) Legal Medicine Journal 3.

30 Butler-Sloss and Hall, n 3; DiMitto, n 5; Freckelton and Selby, n 5; Freckelton, Reddy and Selby, n 2.

31 Abadee, n 5.

(2009) 17 JLM 133 135

Beran

influence upon the overall assessment.32 Such contribution must be acknowledged and attributed to its
source to indicate how, and why, it affected the final opinion.33

If it becomes apparent that any final evaluation would be incomplete without further material
being produced, be it adjunctive history, results of tests or additional existing records, then it behoves
the expert to identify same and to explain why it is needed.34

Once all materials, necessary to construct an opinion, have been made available, the expert should
develop the opinion based upon that available evidence. The opinion needs to be justified and
explained in terms that a lay audience will appreciate and understand, with sufficient clarity to
establish a critical interpretation which is expressed using as simple language as the concept will
allow. Subsequent to the formulation of the opinion, the expert must then answer the questions set out
in the letter of introduction from the lawyer. The responses to those questions should also be explained
so that a lay person can comprehend the nature of the answers and why the expert responded as he or
she did.

It must be reiterated that the expert is not obliged to endorse the position adopted by the
instructing lawyer but it is equally important to reinforce that a competing view will not be introduced
into evidence by the lawyer. On that basis, it may prove most efficient for the expert with a view that
opposes the aims and stance desired by the lawyer to contact the instructing lawyer to explain why
such counter-proposal has been adopted and to seek clarification as to whether a written report is still
required. This is quite different to the expert changing an opinion to satisfy the lawyer, because to do
so would amount to unconscionable behaviour in contravention of any accepted code of conduct.35

A final component in an expert’s report is the provision of compelling evidence to justify why the
expert should be accepted as such and to confirm that the expert has adhered to relevant court rules for
expert witnesses.

THE EXPERT AS A WITNESS IN COURT

The only unequivocal duty that the expert must respect is to answer truthfully any question posed by
any officer of the court, be it the lawyer leading the evidence, the opposing lawyer cross-examining
that evidence or the judge seeking clarification.36

While the expert should attend court with a properly formed and reasoned opinion,37 it does not
necessitate unconditional adherence to that opinion.38 Should further evidence be adduced which
conflicts with that opinion and which is sufficiently compelling, then the expert must recognise the
inconsistency of the previously adopted position and alter the opinion accordingly.39 This does not
translate into a compulsion to accept any conflicting opinion just because it has been suggested, if the
premise upon which that opposing opinion is based is not sufficiently compelling.40 To do so, in the
absence of a convincing argument, would translate into the expert being inconsistent and providing an
inconclusive opinion, in the first instance, and hence would devalue that expert. Only a sufficiently
cogent counter-argument should translate into an altered opinion and the expert should be prepared to
clarify the reason for altering a previously held opinion based upon any additional evidence.41

32 New South Wales Law Reform Commission, n 16 (2005b).

33 New South Wales Law Reform Commission, n 16 (2005b).

34 New South Wales Law Reform Commission, n 16 (2005b).

35 Abadee, n 5.

36 DiMitto, n 5; Barbieri RL, “Thou Shalt Not Bear False Witness” (2003) 15(4) OBG Management 8.

37 Notley, n 20.

38 Burn S, Successful Use of Expert Witnesses in Civil Disputes (Shaw & Sons, 2005) pp 302-303.

39 New South Wales Law Reform Commission, n 16 (2005b).

40 lyer P, Nursing Malpractice (2nd ed, Lawyers and Judges Publishing Co, 2001, Tucson) p 634.

41 lyer, n 40, p 634.

136 (2009) 17 JLM 133

The role of the expert witness in the adversarial legal system

Unlike the lawyer who has instructed the expert, the expert has no particular responsibility to
achieve anything other than a just outcome,42 which need not favour the lawyer’s client. This
re-emphasises the expert’s duty to the court rather than a client. An ill-conceived opinion which is
constantly altered may well result in the expert being of limited value and not being further used.43 A
tarnished reputation is difficult to reinstate and an impeccable reputation is an expert’s most valued
asset.

CONCLUSION

Experts should offer well-constructed opinions based on all available evidence, including independent
evaluation, and be prepared to justify those opinions. The expert has no “duty of care” to endorse a
lawyer’s opinion irrespective of the fact that it was the lawyer who retained the expert. Moreover, the
expert has a responsibility to offer an opinion which is designed to assist the court to discover the truth
within any given case. The instructing lawyer will only use those opinions which advantage the
proposed argument proffered by that lawyer’s client but should still respect the integrity of an expert
who has cogently and forthrightly offered an alternative assertion. That lawyer will be forearmed once
advised of a potential opposing view, as this allows the lawyer an opportunity to develop a
counter-argument.

It follows that the role of the expert witness in the adversarial legal system is to appraise all
available material and to provide an honest and comprehensible opinion which is not unduly
influenced by external factors such as the expectations of the instructing lawyer.

42 Barbieri, n 36; Freckelton and Selby, n 5. 137
43 lyer, n 40, p 634.

(2009) 17 JLM 133