Computerization of Demonstrative Evidence: Changing the Face of Advocacy

Tell me and I will forget, show me and I may remember, involve me and I will understand” – Old Chinese Proverb

The Inevitability of Computer Technology in the Courtroom

Computer technology in the court room is no fad. It will become as much a part of civil litigation as it has become a part of daily life. Nothing lawyers or judges might do can possibly stand against the tide. Any lawyer who ignores this reality does so at his peril.

Many reasons explain why this evolution in advocacy is irreversible, and we lawyers have control over none of them. First, most lawyers under 40 years of age and many young-at-hearts who are a bit older, know and understand computer technology and its applications in every aspect of their lives. We have them in our homes, complete with colour printers and the ability to create professional quality graphic images. We have them in our offices. In short, the world we live in is dominated by the computer. The computer is the central strand in the information age fabric. Because the computer is everywhere and because it has become, despite its complexity, a simple tool of modern life, its absence in the courtroom would be an anachronism.

Indeed the very survival of the civil jury system and the trial adversary system demand the urgent introduction of the computer with its wondrous ability to collect information and convey it quickly, accurately and spontaneously to an infinite number of people. Computer animations communicate technical concepts clearly, quickly and persuasively to a non-technical audience. The evidence permits clarification and analysis of alternative scenarios. Computer imaging also gives jurors and judges the power to add the dimension of time to re-creations of events and moment by moment consideration of an occurrence.

Those who might resist the use of computer technology will do so with the best intentions, but their resistance will be misguided. Lawyers and judges must accept that to the public we serve, the computer, computer imaging and technology in general is a feature of every day life which they take for granted. Jurors are so used to being shown that they are no longer content to just sit back and listen. The question is not whether computer generated imaging should be admissible. The question is what safeguards and tests are required to further the interests of justice.

Computer generated evidence will not only make litigation more efficient, it will encourage settlement. It will enhance the quality of advocacy immeasurably because its persuasive capacity is extraordinary. Because it both shows and involves, it is the most powerful form of evidence available. Why else do the wealthiest advertisers and move makers expend vast sums to create and project computer generated images?

The lawyer who takes advantage of this technology will practice at the leading edge. She will obtain the results to prove it. The lawyer who stays behind will have all the proof he or she needs of the failure to stay abreast of the times.


A. Charts, Graphs, Plans and Maps These two dimensional, static computer generated images make use of the computer’s functions as word processor, graphic illustrator and printer. By using the computer, vast quantities of information can be neatly organized and quickly reproduced for persuasive use in the courtroom. Even the small law office can afford to take advantage of this cost effective way of producing professional quality demonstrative evidence.

In our personal injury practice we produce charts which organize the presentation of much of the plaintiff’s evidence. Treatment charts, medication charts and employment charts synthesize and organize large quantities of important information which span long periods of time. We provide small computer generated versions for the judge, other counsel and members of the jury and print large boards for presentation in court.

There is nothing complicated about the production of these charts. Once our law clerks have inputted the data for the chart it is stored for data to be added as information comes available during the process of getting ready for trial. When all the information is inputted, we go outside the office to have the large boards printed, usually for less than $250. It helps to find a printer who operates the same program, so that no further data entry is necessary. You can avoid a trip to the printer by transmitting the information by modem.

Before we graduated to computer generated charts we had no alternative but to prepare them by hand. The result was better than no chart at all, but the presentation was inferior and we had to start all over again if we made a mistake or had information to add. The computer saves time, improves accuracy and produces a better looking, more credible product.

B. Two Dimensional Drawings and Illustrations

Personal injury and medical malpractice lawyers know the value of this demonstrative evidence in simplifying medical issues and rendering evidence more persuasive. Until recently such illustrations were only available through professional illustrators, but computer software enables the practitioner to produce these images at low cost.

Although not yet in wide use in Ontario, storyboards are a popular form of demonstrative evidence in some American courts. They may come here, because the computer allows generation of these two dimensional images under conditions which guarantee their accuracy and hence their admissibility. Since they have proven persuasive value, it is only a matter of time before creative counsel in Ontario learn how to generate these images and produce them cost effectively.

C. Animations, Simulations and other Sequential Imaging

Forensic animation is generally used to simplify highly technical areas of evidence and is particularly effective where movement and perspective are at issue. These animations have been used extensively in American courts in patent cases, to illustrate human factors evidence in personal injury claims, in motor vehicle accident reconstructions, in explosion and fire cases, and in aircraft, marine, structural and products cases. Virtually any case where motion is involved can be better presented with this technology.

Computer animations were accepted into evidence by Mr. Justice Flannagan in Kingston, in Clapperton v. Bailey and the County of Frontenac, in 1992. I am told that the image, which I introduced as counsel for the plaintiff, was the first computer generated image ever introduced in a civil case in Ontario. I needed the Sight Plans image because by the time I was retained the defendant road authority had removed a mound of earth which obscured visibility at the intersection where the collision occurred. The only available image of the mound was a series of still photographs taken by an adjuster before the mound was removed. Our challenge was to convert the still photographs into a moving visual image from which our engineers could calculate lines of sight and which we could use for persuasive purposes.

Only by seeing this computer generated image can you appreciate the effectiveness of this extraordinary technology. The “virtual reality” of the image is truly awesome. Despite the superiority of the plaintiff’s image, the claim against the road authority failed in this case where damages were assessed at $6.2 million.

Computer generated animations come in many varieties. In some the entire image is computer generated. In others an actual photograph of the scene is the backdrop for the computer generated collision which appears to take place within the real photograph. An aerial photograph of a scene can be used as background so that the vehicles and skid marks can be superimposed over the aerial photo. This technique brings tremendous credibility and impact to the re-enactment. If necessary, the animator can superimpose additional landscaping and objects of note such as stop signs or crossing gates, over a photograph to demonstrate how the roadway could have been made safe for the user. You may use several perspectives or scenarios to clarify issues and demonstrate points of view. Particularly effective is the comparison of alternative scenarios to prove the more probable reconstruction in cases where the parties allege different versions of a collision.

Obviously, these techniques open up many creative alternatives in medical malpractice litigation, where it is often difficult if not impossible to accurately explain the nature of a surgical technique to a jury, or for that matter a judge. Photographs and x-rays can provide the background for superimposed animations. Different views offer the opportunity for alternative perspectives. Alternative scenarios, one being the one the patient expected and the other being the one the patient obtained, are vividly portrayed.

By placing the computer imaging onto videotape, you have ready access to equipment for display and control over pausing, stopping and slow motion by remote control. In a recent case which I will refer to later we rented equipment to project from a VCR onto a large screen. The image it created was far superior to a television image – but we couldn’t for the life of us make it work when we wanted to show the tape. Whatever projection technology you use, make sure it is reliable.

How Do You Create Computerized Simulations and Other Imaging? Not all cases will justify the expense and effort of these sophisticated forms of computerized imaging. However, as the cost of production goes down and the stakes of litigation go up, the effort is more easily justified.

The computerized imaging for the Clapperton case was expensive, but the cost has come down significantly over the last five years. Two simulations I used recently cost well under $5000. The investment makes good sense in an appropriate case.

Whatever you do, do not rely on the illustrator to do both the illustration and the reconstruction. The first step in a motor vehicle case is to obtain an accident reconstruction engineer. These reconstructions do not stand on their own. Because they depend on the data supplied by an engineer, there is no other way but to start with the engineer. In a medical malpractice case this data must be supplied by a medical doctor with the assistance of a medical illustrator. Similarly, in a slip and fall, a human factors engineer might lay the foundation. Start with an engineer in products cases too.

Beware the animator who claims he or she can do it all. One American forensic engineering firm runs an ad in Trial magazine with the words, “Don’t Let an Animator PLAY Engineer with YOUR client”. I couldn’t say it better.

A growing number of engineers doing forensic work have relationships with computer animators. Wise counsel will check out the experience of both contributors and request the opportunity to review past efforts. Some of the best animators are American, but we have animators in Ontario who do a first rate job. Because motor vehicle tort litigation is experiencing a renaissance, the roster will expand over the next few years.

Armed with the accident reconstruction, you and the animator will develop a strategy for illustrating the theory of your case. You review and approve or modify a “draft” view at least once before the final animation is produced. An experienced animator produces a report validating the software, hardware, methodology and confirming the accuracy of the data entry. Experienced accident reconstruction engineers prepare a companion report confirming reliable supervision of the production, establishing the accuracy of the imaging and attesting to cross-checking which the engineer used for verification. In the vast majority of these cases the reconstruction, computer imaging and the reports prepared by the experts will cost between $10,000 and $15,000.

Needless to say, the more information available to the engineer or medical doctor and the forensic animator, the more accurate and reliable will be the computer imaging. Guidance before examinations for discovery from the expert assures that counsel will obtain the necessary data. The Admissibility of Computer Imaging in Ontario

In this section, I offer an analysis of the issues as a basis for determining admissibility, then consider the limited Ontario jurisprudence and the American approach, and finally offer some strategies for admissibility for the benefit of counsel.

A. An Analysis of the Issues

Confusion abounds. Lawyers and judges refer to this evidence by a variety of its popular names: computer simulation, animated simulation, computer generated reconstruction, computer generated graphic visualization, computer re-enactment, scientific computer animation, computer imaging. None of these descriptors assist us with the evidentiary issues.

When I introduced the computer imaging in the Clapperton case, I just did it. Sort of Nike v. Nike, if you like. I gave only cursory thought to the deeper evidentiary issues. If I had reviewed the literature, all of it American, and looked at the cases, all of it then being American, I would have discovered that there has been a failure on the part of lawyers and judges to resolve questions of admissibility based on an analysis of two things: a) the nature of the computer generated image, and b) the purposes for which it is led as evidence. As I will discuss later in this section, these issues were not clarified in the only Ontario decision to grapple with the admissibility of this evidence. We must establish a proper foundation in Ontario law based on these fundamental questions if we are to avoid the confusion which pervades the American case law.

Simply put, the party tendering the computer generated image must declare whether the image is tendered to prove something by itself or to merely illustrate other evidence that is proven by the expert who introduces the image. For example, in a motor vehicle accident case, plaintiff’s counsel should know and declare whether the computer generated image proves something by itself or merely illustrates the reconstruction testimony of the accident reconstruction engineer.

The use of the term “demonstrative evidence” confuses the issue, unless we are content to use that popular phrase to designate any and all visual evidence, in which case it is of no assistance on the question of admissibility. When you get down to it evidence is either substantive evidence or illustrative evidence. Categorizing evidence as real or demonstrative only confuses matters, because much so-called real evidence is used for demonstrative purposes. Substantive evidence has probative value of and by itself. Illustrative evidence has no independent probative value and merely supports or illustrates some piece of substantive evidence.

If the evidence is merely illustrative of otherwise proven substantive evidence, the test for admissibility should be more relaxed. For such evidence, providing the evidence is not unfair or misleading, and providing it is relevant and helpful to the trier of fact, it should be admissible if it accurately illustrates otherwise admissible substantive evidence. The key to the admissibility of computer generated imaging which is merely illustrative is a determination that the underlying reconstruction is admissible and a determination that the image fairly portrays the event as reconstructed.

Courts should have no difficulty admitting computer generated imaging which is illustrative. Greater difficulty will arise in relation to imaging which is intended to be substantive evidence. Computer generated imaging will be presented as substantive evidence in those cases where the imaging is based on software which is so complex that the expert does not understand it, cannot verify the accuracy of the re-enactment or his conclusions based on the computer results. Then the expert’s testimony is based on the computer imaging, and the expert’s conclusions depend on the admissibility of the computer imaging as substantive evidence.

Although I didn’t realize it at the time, I was using the computer generated image in the Clapperton case as substantive evidence. My expert’s calculations of site lines depended on the accuracy of the computer generated image of a landscape which had been destroyed before my expert was retained. My skilled opponent also tendered an animation, which I now realize was offered merely to illustrate his expert’s opinions.

No compelling justification exists for dismissing substantive computer generated imaging out of hand. We have too much faith in and understanding of technology for that. Criminal courts accept DNA analysis evidence, without understanding DNA technology, as a matter of course. However, the party tendering the imaging must disclose sufficient information concerning the software, the hardware, and the relevant professional community’s acceptance of the software, so that an opposite party can test the validity of the image prior to trial.

Furthermore, where substantive computer imaging is tendered, a court should not permit any imbalance where one party is less financially able. In such cases a court should ensure that the tendering party has made the necessary information, the computer program and the hardware available well in advance of trial. In addition, if required, a court should grant the receiving party the right to use both the hardware and the software for purposes of cross-examination and trial. Some judges will feel threatened by this evidence. But when the dust settles on this debate the courts will admit this evidence as freely as much of the other scientific evidence which our courts readily accept.

B. The Current Law

According to two published American authors, little American case law directly addresses whether and when computer generated imaging will be admissible.1 The authors discuss several cases where the issue of admissibility is examined.

In Perma Research & Development v. Singer Co. (542 F.2d 111 (2d Dir. 1976) cert. denied, 419 U.S. 987 (1976)), the issue was Perma’s right to cancel a contract, which it alleged Singer had breached because it could not perfect a device. At trial, Perma relied upon computer simulations that the anti-skid device was perfectible, in support of it’s claim that Singer had not used best efforts as the contract required. Perma succeeded so Singer appealed, primarily on the argument that the computer simulation should not have been admitted because it had not been given the underlying data and computer programs before trial and was thereby denied the opportunity for meaningful cross-examination. The appellate court didn’t buy Singer’s argument, but made it clear that this information should be made available to the opposing party prior to trial.

In Pearl Brewing Co. v. Joseph Schlitz Brewing Co. (415 F. Suppp. 1122 (S.D.Tex. 1976)), computer generated models were used to simulate market conditions in an antitrust action. Before trial the defendant applied for discovery of the detailed structure of the computer model. The court granted the motion.

In a recent leading decision, Daubert v. Merrell Dow Pharmaceuticals Inc. (113 S.Ct. 2786, 2796-97 (1993)), the U.S. Supreme Court set forth specific factors to be considered, as follows: Faced with a proffer of expert scientific testimony…the trial judge must…(make)…a preliminary assessment of whether the reasoning or methodology underlying the testimony is scientifically valid and whether that reasoning or methodology properly can be applied to the acts in issue….The inquiry envisioned by Rule 702 is…a flexible on. Its overarching subject is the scientific validity – and thus the evidentiary relevance and reliability – of the principles that underlie a proposed submission. The focus, of course, must be solely on principles and methodology, not on the conclusions that they generate. In Ontario, there are now three cases which consider the admissibility of a computer generated image. The first is the decision of Mr. Justice Kozak in Owens v. Grandell ([1994] O.J. No. 496 (Ont.Ct. Gen. Div.) Quicklaw). His Honour concluded computer generated imaging will be admissible, if:

  1. the data points measured at the accident site were accurately recorded;
  2. the data points were entered into the computer correctly;
  3. the algorithms used in the form and motion software validly apply the law of physics and validly render accurate images of the scenes depicted in the exhibit; and
  4. the imaging will assist the trier of fact in understanding the expert’s testimony.

Mr. Justice Kozak was considering the admissibility of evidence which he consider to be illustrative of other substantive evidence given by the accident reconstruction engineer. Mr. Justice MacKinnon considered the admissibility of a computer generated image in a personal injury action in Barrie, Ontario, where I acted for the plaintiff. I hope it is true that we learn more from our mistakes than our successes, because the imaging was ruled inadmissible due to my own error. In Smit v. Delguidice ((1996) unreported decision of MacKinnon J. (Ont. Ct. Gen. Div.)), I overlooked the absence of a report from the American animator who prepared my animation (such a report isn’t required in the U.S. courts I have learned) and I failed to ensure the reconstruction engineer had checked the animation for accuracy. It didn’t help that an error was discovered in the animation the night before we tried to put it in. In his ruling, Mr. Justice MacKinnon provided the following guidance to counsel concerning the admissibility of computer generated imaging: The factors that the Court considers on this matter are as follows:

  1. Is the evidence admissible? That is considering the factors of relevance, accuracy, and whether or not the video has the capacity to, and does mislead.
  2. Can the facts be verified by persons capable of doing so?
  3. Thirdly, is the video necessary to assist the Jury in understanding Mr. Bender’s evidence?
  4. Does the video contain editorial comment?
  5. Will it shorten the trial?

Mr. Justice Shaughnessy considered the admissibility of a computer generated animation in a recent products liability action in Barrie, Ontario, where I acted for the plaintiff. In McCutcheon v. Chrysler Canada Ltd, ([1998] O.H. No. 5818 (Ont. Ct. Gen. Div.) Quicklaw), the plaintiff suffered a crush injury to his pelvis when his parked automobile slipped out of gear and reversed on to him. The plaintiff suffered from Polio as a child and his crush injury led to Post-Polio Syndrome as an adult. Although he walked with a limp pre-morbidly, the injury left him with a markedly increased limp.

The computer generated animation which I introduced illustrates the pre-morbid and post-injury gait of the plaintiff. It depicts a computer humanoid figure visually presenting the gait of the plaintiff before the injury, as well as after the injury. The scene changes at various times to show the bone structure of the legs and feet pre- and post-injury and also at one point shows an actual picture of the plaintiff walking with his brace on. There are also split-scene comparisons on the screen showing the humanoid in gaits pre- and post-injury.

Mr. Justice Shaughnessy allowed the computer generated animation into evidence and applied the reasoning in the cases of Smit v. Delgiudice and Owens v. Grandell. He concluded that the computer generated animation would assist the jury and provide some evidence by which to compare the pre-morbid and post-traumatic gait of the plaintiff. Mr. Justice Shaughnessy was satisfied that the hardware and software methods employed by the animator were verified by him on the stand. He was also satisfied that the computer animation accurately represented the plaintiff’s pre-morbid and post-traumatic gaits and that the animation would greatly assist the jury in understanding the issues. Lastly, he found the animation was not misleading or unfair to the defendant, it was not inflammatory and it was no different then what the jury might see on a television commercial. Any perceived frailties in the evidence would be subject to cross-examination and would go to the weight of the evidence, not its admissibility.


A review of the cases from the Western Provinces revealed one decision which cites Owens v. Grandell. In Crosby v. Joyce ([1997] B.C.J. No. 2567 (B.C.S.C.) Quicklaw), the plaintiff in a personal injury action applied to tender a computer generated video of a reconstruction of a motor vehicle collision. An expert in the field of accident reconstruction created the computer video.

The court did not allow the computer video into evidence. In relying on Owens v. Grandell, Justice Sinclair determined that the admission of the video “might confuse, mislead or overwhelm the trier of fact”. The court did not allow the video because the computer generated reconstruction depicted only the vehicles of the plaintiff and the defendant. It did not depict any other traffic. The presence of other traffic was a contentious issue between the parties and the court concluded that its omission from the reconstruction rendered it unhelpful and potentially misleading to the trier of fact.

In Green v. Winnipeg (City) Police Department ([1996] M.J. No. 219 (M.C. Q.B.) Quicklaw), the plaintiff sought to introduce into evidence a computer generated animation. The plaintiff suffered a dislocation of his spine that left him with severe injuries after the police arrested him and an officer placed him in an arm lock for the purpose of handcuffing him. The plaintiff sought to introduce a witness at trial who was an expert in scene reconstruction. The witness used computer software to provide graphic simulations in order to describe the interaction between the plaintiff and the police and to illustrate the plaintiff’s injuries.

In not allowing the computer animation, Justice MacInnes held that although other cases have dealt with the admissibility of computer generated simulations, the court would reach its decision on the basis of the criteria regarding the admission of expert evidence offered by Sopinka J. in R v. Mohan ((1994) 2 S.C.R. 9).

The court accepted the qualifications of the expert and the accuracy and scientific validity of the computer software program used in the animation. However, the finished product did not provide an acceptable or sufficient degree of reliability or faithfulness in its reproduction of the scene and especially in its reproduction of the interaction of the plaintiff and defendant police officer. The expert determined many critical elements of the animation by inputting subjective information based upon his own judgment. The end result was an animation that was highly subjective and scientifically unreliable in showing the motion, movement and interaction between the parties. The court found the animation was misleading in the sense that its effect on the trier of fact was out of proportion to its reliability. As a result, the animation had little probative value and much prejudicial effect in light of the issues in the case.

I know of no case in Ontario, or indeed in Canada, where a court sets out the principles for admission of computer generated imaging as substantive evidence. However, we find some guidance in the reasons of the Supreme Court of Canada in R. v. Mohan. Justice Sopinka reasoned that the admissibility of novel scientific evidence depends on the proven reliability of the science. Because the result in cases may turn on the admissibility of computer generated imaging, we are sure to see the case law in this area develop rapidly.


  1. Meet with the expert and the animator to ensure both understand their role and obligations and that both are comfortable with the animation. Cautious counsel will ensure that the animation is presented in real time and that a chronograph records time on the image. This technique guards against a potential abuse. (If slow motion is required for a particular purpose, a chronograph should be used to ensure the animation is not misleading). Cautious counsel will also ensure that all details and perspectives fairly reflect what was there to be seen by the parties when an event occurred. Every precaution should be taken to ensure that extraneous elements, particularly those which might be considered unfair or inflammatory, do not appear in the imaging. Ensure the animator employs the laws of motion; in other words, ensure the animator does not take an overly simplistic approach to the motion of objects under force.
  2. At the meeting with the expert and the engineer, decide whether the computer generated image is substantive evidence or illustrative of the expert’s opinion.
  3. Ensure this issue is clarified in the report prepared by the accident reconstruction engineer or other expert as well as the report prepared by the forensic animator.
  4. Have the animator and the expert who has supervised the production of the image include in their reports a check list. Follow the check list when laying the foundation for admissibility during oral testimony. Review the check list at the meeting and ensure that it will be followed religiously. Since engineering reconstructions are seldom precise, and usually employ ranges of data, ensure that the animator and engineer are confident that the animation reflects the conservative end of the range.
  5. The check list must confirm: (a) that the data was entered accurately; (b) that the data is within the personal knowledge of the witness and itself is accurate; (c) that the program has been approved by peer review; (d) that the hardware was working properly; (e) that the results were checked; and (f) that the image fairly and accurately depicts the occurrence.
  6. Counsel must comply with the Rules by serving a copy of the computer generated imaging, the foundation reconstruction, the report by the animator and the report by the expert confirming the reliability of the animation.
  7. Counsel should also offer to provide information concerning the software and hardware employed.
  8. Although it should not be required for admissibility, prudent and cautious counsel will make the expert and animator available to opposing counsel or opposing counsel’s expert for explanation.
  9. Counsel should take care when leading the evidence to lay the foundation slowly and incrementally. One proven American technique is to begin by introducing sequential still images and then demonstrating how, when they are shown quickly together, they result in a moving image.

The technology for producing sophisticated computer generated images is well ahead of the legal system’s study of the subject and the common law’s readiness for these images as evidence. For the time being counsel and judges must resort to first principles to ensure fairness.

Not long ago a flip chart and an overhead projector were at the leading edge of demonstrative evidence. If our courts are to remain relevant to the society they serve we must contend with a new leading edge which depends on advanced computer technologies we could not dream of a decade ago. Cradled in the common law’s infinite capacity for orderly evolution, adaptation and change I have no doubt that our courts will cope with the challenge. Counsel who grasp and harness the power of this new medium to persuade and who possess the skill to guard against its abuses will be ready for litigation in the age of computer technology.

  1. R. Simmons and J.D. Lounsbery. “Admissibility of Computer-Animated Reenactments in Federal Courts.”, Trial Magazine, September, 1994, p. 78. GO

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