Expert Witness Advocacy

During the course of education and training of a forensic scientist, substantial care and attention focuses on aspects of scientific discipline. Familiarity with appropriate laboratory procedures, strict adherence to professional guidelines and standards, correct application of methodology and instrumentation and the detailed completion of scientific reports all receive significant emphasis.

Having regard to the fact that the forensic scientist is regularly called upon to explain his or her observations and opinions in a courtroom setting, however, by comparison relatively little time is spent on the most effective way in which to communicate scientific expertise in the giving of testimony. What follows is intended to provide an overview of the many considerations to be addressed in the role of scientist as witness.

There is a substantial likelihood that a young forensic scientist is told by his more experienced colleagues, by way of an offer of reassurance to overcome the apprehension that may accompany the service of the first subpoena or court notification, "don’t worry - the more you testify, the better you will get". Notwithstanding that training methods in the delivery of evidence may be conducted by more senior forensic scientists, it is less common that prosecution and defence counsel, particularly those that are trained in the teaching of trial advocacy skills, are involved in this portion of education. As a result, not only does the young scientist risk learning by unpleasant experience but, further, early errors may not necessarily be rectified by repetition.

In fact, the process of giving oral evidence in a courtroom setting is so unlike ordinary human experience that it could properly be considered rather "unnatural". The witness is restricted to answering only the questions asked, subjected to often vigorous confrontation on cross-examination by a lawyer fully comfortable with the trial process and familiar with the rules of evidence and procedure, areas in which the scientist has received little or no formal instruction. Strangers or observers of the process and the trier of fact, whether a judge or a jury, will be called upon to carefully scrutinize every word of the testimony as well as the demeanour in which the evidence is given. In the absence of meaningful instruction or critique from a trained educator, increasing experience may be something akin to a golfer with a very fast swing. His game will never have the opportunity to improve, no matter how much he plays, in the absence of meaningful instruction.

It is hoped that the principles outlined below will have direct practical application which, with some modifications depending on the system of justice in place, may still prove to have universal value. However, the perspectives offered are based on experience in the prosecution and defence counsel roles in the Canadian criminal justice system.

Under Canadian law, an expert witness must be found by the Court to be properly qualified to possess sufficient skill and knowledge as to be able to express an opinion, an area of evidence not generally permitted to the lay witness other than in matters of general and ordinary experience. Further, the opinion to be expressed must be of an area which is relevant to the issues to be decided by the Court and beyond the expertise of the trier of fact. The evidence will be the subject of scrutiny on issues of reliability, particularly if it is proposed to advance a novel scientific theory or technique and, further, must be considered to have sufficient probative value that it would outweigh any prejudicial effect. Before the witness is allowed to express an opinion, counsel will be called upon to lead from the witness evidence of his or her qualifications to give the opinion on the particular subject at hand. The witness will be limited to those areas within his or her qualifications, however might be called upon to answer questions beyond the scope of expertise.

The witness will be permitted to give evidence about physical observations involving the use of equipment or methods which call for a particular skill and experience which have been performed by a properly qualified individual. The witness may choose to refer to rely upon the texts, research, consultations with recognized source material and even information provided by counsel. The witness may be called upon to answer questions involving hypothetical fact situations. However, to the extent that an opinion is based on a hypothetical facts, a judge or jury must be satisfied that such facts have been properly established, as a failure to accept such facts will result in a reduction of the weight to be given to the opinion of the witness. Otherwise, an expert is considered the same as any other witness. A jury is told that they may choose to believe some, all or none of what the witness has said and can reject the witness’s evidence even though no other contrary expert evidence is introduced.

Under any system of justice, it is critical for the forensic scientist to be aware of what may be characterized as "the purpose of the exercise" namely what is the basis upon which the evidence is being offered and on what basis may it be considered by the Court. All aspects of the scientist’s experience which may be referable to the trial proceedings should be conducted with this ultimate purpose in mind.

Quite apart from the basis for the admissibility of the evidence, in any legal system of justice, whether inquisitory or adversarial, involves the determination of issues based on evidence. In essence, the oral presentation of evidence involves the use of language and, even more specifically, the precise use of language. Every witness, whether civilian or scientist, must always be cognizant of the fact that it is the specific language that is used which comprises the evidence, not inferences, assumptions or extrapolations. The words used are considered by the trier of fact and constitute the record of the trial for the purposes of appellate review. Accordingly, the decisions made by the witness on the way in which to express his or her evidence are critical to the trial process and the accurate expression of opinion.

In addition, the manner in which the evidence is given has its own particular significance to the presentation of testimony. It is my view that an expert is not there simply, to use the Shakespearian phrase, to "strut and fret his hour upon the stage" by delivering answers to questions without consideration of the effect that the manner of such expression may have on the listener. The trier of fact will ultimately be called upon to decide what, if anything, of the witness’s evidence is to be believed. It should matter to the witness whether the evidence he or she is presenting is understood and accepted, particularly in regard to the time spent in the formulation of the opinion and the scientist ought not to truly be indifferent to the results of that determination, quite apart from the disposition of the case.

Without question, the expert’s evidence is of significance to the counsel who has chosen to call him. Presumably, having regard to pre-trial interviews together with the review of the report and relevant research, counsel has decided, using her judgement and expertise, what the witness has to say will be relevant to the case and of some benefit to the cause, whether the establishment of guilt or questioning the level of proof in the case for the prosecution.

At the very lease, she is entitled to expect the following:

the witness has a scientifically valid basis for his opinion. The opinion falls within a recognized area, the witness has carried out such observations and tests as are necessary, utilizing experience, training familiarity and, as appropriate, consultation with others;

the expert is possessed of sufficient expertise that he can and will be qualified by the Court to give the opinion’

that the expert will give the opinion in Court in the same terms as indicated in the report, consultation with counsel or both including specifically,

that were particular language has been used to represent a level of certainty, the witness will maintain the same language, at the very least on examination-in-chief, with the same degree of certainty;

the witness will make at least a token effort to maintain that opinion under the rigours of cross-examination, assuming there has been no horrendous error or that counsel has not provided accurate or complete information to the witness.

In addition, although time and intellectual restraint might place some limitation on what the expert can provide, it is desirable that some effort is made to:

point out to counsel the limitations, shortcomings and possible problems with the opinion that is expressed;

make an effort to get on the "same wavelength" with respect to terminology as counsel. She may use words that are part of ordinary parlance for the layperson which may have special significance to the expert. Ideally, counsel will assist the expert in keeping his language clear and understandable. Counsel will also assist in the presentation of such qualifications and aspects of testimony as may follow in a logically progression, ensuring that the witness has been fully briefed on all significant evidence as well as the likely points upon which cross-examination may be anticipated;

during the course of examination-in-chief, should counsel vary slightly from the terminology or fail to direct the witness specifically to an area that the witness knows, from prior discussions, are significant, it is perfectly appropriate for the expert to help her out to some extent by attempting to deal with the issues in a fashion which may flow naturally from the course of the testimony. Although it has been known to happen, it should not be necessary for counsel to write out every question to the last word in order to provide some measure of certainty that the witness will give the same answer in Court that was provided in the office. Some lawyers have been known to ask a witness, with a moderate degree of frustration, "what question do I have to ask you for you to give me that answer once we are in Court?"

Having behaved with the utmost professionalism and responsibility during the course of the laboratory to the point of completing and documenting all research upon which the report is based, there is a different form of challenge facing the scientist in the course of testifying as a witness.

In that regard, it could fairly and properly be stated that the forensic witness is essentially an advocate, not only a scientist. It is not suggested that the witness in such circumstances is the proverbial hired gun, paid or retained to put forward the best possible position to benefit the client notwithstanding that that may mean straining the bounds of reason or stretching language to the breaking point - that may be a matter best left to counsel.

Rather, it is fair to say that the expert is an advocate with respect to the opinion which he expresses as well as his own credibility in doing so. That approach is applicable whether the witness is on permanent staff of a government lab or retained on an independent basis to provide consultation in individual cases.

If truly makes a difference in a Court as to how the evidence is given and not simply by the specific use of language. An expert on the witness stand is essentially advocating that his views are:

sound, i.e.: they are reasonably based on the evidence in the case as the witness understands it. ;

the opinion is scientifically valid;

the opinion is preferable to alternative views;

the opinion is couched in a valid level of certainty which can be properly considered as "appropriate" in all the circumstances.

Furthermore, the expert certainly is presenting himself as a forensic scientist whose opinions are worthy of acceptance or, at the very least, respect as a professional possessed of knowledge, skill and integrity.

It is from this standpoint that the witness develops and maintains a reputation in the Courts which can facilitate, or alternatively devastate, his continued involvement in future proceedings. Lawyers and judges are notorious for sharing stories about the fairness and professionalism (or otherwise) of witnesses who have testified in Court and judges have particularly long memories.

What’s more, court reporters provide transcripts which can be used in future proceedings for confrontation and challenge to credibility.

Accordingly, even a single demonstration of bias, inefficiency, overreaching or ignorance has the potential to undermine the witness’s future effectiveness and reliability.

To summarize, the witness must remember the purpose of the exercise including his role in the trial process. He must work together with counsel to ensure the most clear and accurate presentation of the testimony. On the witness stand, the expert must behave with the utmost professionalism having regard to the effect not only on the immediate trial but future proceedings for the sake of just results and the preservation of a proper reputation.

The preparation process for the presentation of testimony begins with the witness’s very first involvement in the investigation. Having regard to principles of criminal procedure whereby the prosecution and defence have access to notes, memoranda, test data and other materials which may be developed during the course of investigation, the conclusion of the process must be kept foremost in mind even at the outset.

As a result, it is of critical importance that complete notes and records, diagrams, photos, sketches, measurements and samples as well as detailed descriptions of procedures must be retained for the purpose of possible review. Even in the event that evidence on examination-in-chief might focus particularly on the conclusions with a more general summary of methodology, the reverse may become the subject of closest scrutiny by cross-examining counsel. A challenge to methodology, fairness and the ability to recall or present what investigative steps were carried out months or even years before may provide the basis to arouse disbelief.

The expert’s report must be fair, complete and accurate, especially with respect to the language utilized. Just as the trial process with its focus on the language of testimony requires precision, so to should the report maintain that same level of precision. In almost any jurisdiction, that report provides a basis for examining counsel to appreciate what may form the subject to testimony that, at the same time, may provide the foundation for cross-examination by opposing counsel.

In an ideal setting, the expert should endeavour to prepare his examining counsel and, as appropriate, seek an opportunity to do so. Pre-trial consultation gives the witness an opportunity to explain his views in language which may more readily be understood by counsel and, in turn, with the trier of fact. In addition, counsel and the witness may be able to streamline the evidence by omitting such extraneous scientific background information as may only serve to confuse.

In addition, such consultation may enable counsel to understand those highlights of the curriculum vitae which may facilitate qualification of the witness by the Court to give expert opinion testimony. In addition, examining counsel may benefit from a review of text or general references to better understand the evidence to be introduced.

A major ethical dilemma may arise when counsel attempts to develop an opinion which is at the outer reaches of the witness’s level of certainty. Phrases which may provide some indication include "I don’t want to put words in your mouth but..." or "So what you are really saying is...". In this sense, the expert is most certainly not an advocate of the cause. The witness may ask himself, "Would this opinion stand up to scrutiny by another equally qualified expert retained by opposing counsel? Is the opinion which is being requested within my area of expertise and a fair reflection of the state of scientific knowledge upon which I feel qualified to express an opinion?"

It is desirable if counsel outlines to the witness the areas intended to be addressed during the courses of testimony along with the sequence under which the issues will be covered. As necessary, the exhibits which may be utilized may be reviewed again to confirm that the opinions to be expressed are still valid.

Finally, before testifying, a sound practice would include a review of the file memoranda, notes and test results together with the report as these materials may properly be used by the witness in Court during the course of giving evidence.

It may be most convenient to list suggestions which may be beneficial to the witness on the stand. Many of these comments are equally applicable to civilian or police witnesses and even serve to assist in the performance of counsel.

Habits such as failing to make eye contact with examining counsel, jingling loose change in one’s pocket, fiddling with a pen or exhibits, et cetera may similarly serve to distract.

The witness should be cognizant of his demeanour. Is he too arrogant? Too intellectual? Too confrontational? Too uncertain? Not every witness has the capacity to engender affection but the desire certainly should still to be avoid arousing animosity. A proper attitude to maintain would include qualities such as sincerity, fairness, impartiality, confidence and thoroughness. A polite, relaxed toned may enable the judge or jury to be more receptive of the evidence presented by the witness.

Consideration should also be given to manner of speech. Qualities including volume, pace, clarity, emphasis and expression may assist in a judge or jury understanding the evidence.

The expert must concentrate on every word of every question. On examination-in-chief, it is appropriate to consider what the examining counsel is seeking to elicit. The witness should not "jump ahead" too far; counsel may choose to introduce the subject or specific features on a step-by-step basis and the witness should permit her to do so. It may be advantageous to pause with a sufficient level of frequency that counsel may not have to interrupt should clarification be desired. It is sometimes possible to discern from observing the judge or a jury whether the evidence is being understood and, if not, how to provide a better or more understandable explanation.

Response to questions - the most preferable answer is one which provides a concise and precise response. A witness need only answer what is being asked and collateral or irrelevant considerations ought not to be included. Ideally, response should be applicable to the evidence or facts in the case. As appropriate, a point form outline will assist in the judge or jury being able to retain the opinion proffered. In Canadian jury trials, the trial judge is required to review with the jury the significance evidence introduced during the course of the trial and the expert has the capacity to assist in this regard by the clear presentation of evidence.

There are a range of areas which may form the basis for attack by opposing counsel. These include challenging the witness’s qualifications, his personal experience, bias, inaccuracy, lack of thoroughness and even the general subject of his discipline.

Further, the witness may be challenged with respect to his opinions having regard to scientific validity, the existence of alternative opinions, the evidence at the case at bar and even the issues of commonsense.

It may be worth remembering that the expert has the ability to control the pace of the cross-examination by the speed with which the questions are answered. The witness has every right to be deliberate and thoughtful, answering in a considered and measured fashion. Cross-examining counsel seek to generate momentum by asking questions which may call for very brief answers. These may not always be fair or appropriate by way of response to the question in the form in which it is asked.

That being said, if a question on cross-examination can beanswered succinctly, regardless of whether it evokes the feeling that the witness is making too great "a concession", the fair answer should be given without hesitation. A witness who constantly takes issue with counsel’s terminology may begin to take on an adversarial posture in the eyes of the judge or jury.

Lawyers regularly seek to use phrases such as "Is it fair to say...?" or "Is it possible...?" in the hope of extracting an affirmative response. The form or style of question they play on a witness is designed to appear fair. Appropriate caution should be utilized in the formulation of response. The latter form of questioning may be based on a potential lack of absolute certainty in matters of science. One senior scientist, when challenged repeatedly on matters of possibility, simply responded, "Almost anything is possible. If you ask me if I can take my pants off over my head, that’s not possible, but aside from that, almost anything is possible." Another senior expert chose to answer more benignly on a matter of possibility, "I would suppose that is possible, but I can only say that in the hundreds of similar examinations in which I, for the record, have been involved, I’ve never seen it."

Some cross-examiners seek to entice the witness to the very limits of his expertise and beyond in the hope of taking the witness outside of his zone of confidence which is based on his skill and training. It is perfectly appropriate and in fact recommended, particularly keeping in mind the role of the witness in the Court process, to indicate that that question calls for a response beyond the witness’s expertise. Some questions may simply be phrased in a way that, having regard to the witness’s area of knowledge, a meaningful response cannot be given.

The use of hypotheticals form a frequent basis for cross-examination. In this regard, it is essential to take into consideration all components of the question in the formation of any response which may, quite appropriately, denote the phrase "On the basis of all of the factors outlined in the hypothetical I am assuming them to be established..."

Some counsel chose to interrupt the witness or attempt to unfairly limit his ability to respond. Universal recourse available to the expert in such circumstances is simply to request of the Court (or counsel), "If I might be permitted to explain." Few judges, if any, would prevent an expert for offering an explanation where requested.

As the case on examination-in-chief, the expert should be conscious of his demeanour and attitude. At all times, it is desirable to appear fair, objective and even conservative in the expression of opinion. In fact, the more cross-examining counsel becomes harsh or aggressive, the more the witness may choose to conduct himself in a polite and restrained manner.

In the Canadian system of criminal justice, the trial process permits the counsel who has called the witness to re-examine in order to clarify certain responses or to deal with new issues which have arisen on cross-examination. This may provide some degree of reassurance to the expert during the course of cross-examination in that there will remain an opportunity to provide a further explanation, should counsel wish to provide it on re-examination.

In summary, the role of the expert witness in Court provides a unique series of challenges, requiring a blend of skill in matters of science, reason, language and communication.

While there is no assurance that there will be improvement in the performance of the witness simply by repetition of any experiences. Rather, the expert witness benefits from both initial and ongoing training and evaluation coupled with the underlying awareness of his role in the trial process.

Over time, the experience of testifying in Court as an expert witness might even become enjoyable!

Jeffrey Manishen is a partner at Ross & McBride LLP.  He practises in the area of criminal law.  Jeff can be reached at (905) 572-5813 and jmanishen@rossmcbride.com