CLE Online Seminar - 1999

E. X. Martin, III
Attorney at Law
8828 Greenville Avenue
Dallas, Texas 75243
214-343-7400 - Voice Ô 214-343-7455 - Fax

(Show Them - DonÌt Just Tell Them)

No matter how believable your clientÌs evidence is, you will not be successful in trial if the jury isnÌt listening. Computer generated forensic recreations and simulations are dramatic, persuasive, and can be used as demonstrative and scientific evidence in both civil and criminal cases.# Recreations and simulations convey information more effectively, memorably, and persuasively than oral testimony alone. In some cases, computer generated visual evidence may be the only way to convey certain information to the court or jury. Computer generated recreations and simulations can be used to illustrate and explain a lay witnessesÌ testimony or an expertÌs opinion. Recreations provide an additional benefit for trial lawyers because they can be shown to the jury in real time, slow motion, or one frame at a time. The use of computer simulations and recreations for better jury understanding will help you succeed in the courtroom.

The kind of computer generated graphics this section of my presentation refers to are useful in helping others to understand a particular sequence of events. The automobile accident that caused Princess DianaÌs tragic and untimely death was illustrated by various types of computer generated simulations and animations. Millions have seen the computer generated simulation that showed her vehicle striking the right hand side of the tunnell in Paris and then careening into a supporting pillar. While no one can understand why this tragedy took her from us, the simulations helped us visualize how the fatal impact occurred.


Personal Computers have dramatically altered the manner in which we practice law. Computers assist us with word processing, calendar or docket management, financial accounting, and legal research. Advances in technology have made desktop computers powerful and affordable. Computers are now being utilized by criminal defense attorneys throughout the United States to produce forceful and effective computer generated forensic recreations and simulations for use as sophisticated visual evidence at trial. An expensive main frame computer is no longer necessary for the production of these graphic recreations. A personal computer and software package that costs less than $10,000 can now create excellent recreations and simulations. Recreations that would cost $50,000 a few years ago can now be produced for $3,000 or less and this cost will continue to go lower.

I believe in the phrase Ïshow them, donÌt just tell them!Ó often voiced at CLE seminars by lawyers speaking about demonstrative evidence. I also believe that jurors retain longer evidence that they both hear and see. Jurors are much more accustomed to receiving information from television than they are listening to testimony. Forensic recreations and simulations are created on a computer utilizing specialized software and then recorded onto video tape or a digital video disk and shown to the jury using a television monitor. They are three dimensional and physically accurate. The recreations are interesting and attention getting and can give you a distinct advantage in the presentation of your case.


Scientific formulas drive computer simulations. Simulations are viewed by the courts as scientific evidence. They demonstrate an expertÌs opinion and are used to dramatically illustrate how objects, things, or human models move and interact according to certain scientific principles and formulas. For a computer simulation to be admitted into evidence, it must be sponsored by an expert witness. The predicate for admissibility will focus on the underlying scientific principle and the reliability of the expertÌs application of these principles as depicted in the simulation. Computer simulations are frequently used to illustrate automobile and airplane crashes. This graphical presentation of your expertÌs opinion is probably the single most important aid in the presentation of your case.

Mark J. Mahoney of Buffalo, New York, successfully used a computer simulation while representing a truck driver who was indicted for vehicular homicide. His client was driving a truck loaded with 43,000 pounds of cargo and his truck had rolled over while negotiating and entrance ramp to an expressway and crushed a passenger car. The two passengers in the car were killed. Mr. Mahoney used the computer simulation to show the real possibility that the truckÌs load shifted and this caused the truck to turn over. The computer simulation in conjunction with the sponsoring expert witnessesÌ testimony discredited the prosecutions theory that the driver was speeding. The jury returned a verdict of not guilty.


Computer generated recreations are viewed by the courts as demonstrative evidence. Generally they are scenes relevant to the case that have been recreated from live testimony or unimpeachable evidence such as a live video tape. To be admissible, demonstrative evidence must be shown to be accurate and relevant to the issues involved in the case. Computer recreations generally embody 3-D cartoon like mannequins that have been used to demonstrate what a witness says took place. The basic predicate for admissibility is that the recreation fairly and accurately represents the factual situation observed by the witness. I suggest that the attorney offering the recreation lay a predicate for admissibility with eyewitness testimony, expert opinions, or both to prove the recreation is factual, realistic, and accurate. Additionally, you must convince the judge that the recreation will aid - not confuse - the jury.

I have used a computer in a felony assault case to support our contention that my client shot the complainant in self defense. My computer generated recreation was offered and admitted as demonstrative evidence. I used two witnesses to support the admission of the recreation into evidence. I called the animator who constructed the graphic images as a witness to establish the accuracy of the appearance of the physical objects appearing in the recreation. This witness also testified that the mannequins shown in the recreation were in proportion to the actual height, weight, and build of the actual people involved in the altercation. The defendant testified that the recreation was substantially similar to the conditions existing at the time of the alleged assault. He also testified that the recreation fairly and accurately represented the attack on his person subsequent beating.

The facts of this case established that the defendant had received a telephone call at night from a former girlfriend who had been beaten by a man (the complainant in the criminal case) with whom she was living. The woman asked my client, the defendant, to come to her house and take her away because she feared the man would kill her. The man took the phone away from her while she was talking and told the defendant that if he can over he would kill him. The defendant, a native Texas, stuck a pistol in his belt and went to help his former girlfriend.

He parked his car by the driveway and approached the house, looking for her. She had left the house and was hiding in a vacant lot across the street. She called to the defendant, causing him to turn his back to the house. At that moment the complainant attacked him from behind, knocking the defendant to the ground.

The man got on top of my client and began viciously beating his sead with his fists. My client succeeded in knocking the man off, stood up, and fired a shot that struck his attacker in the leg. My client was able to drive away from the scene to a friendís house, who took him to a hospital.

The following screen snapshots are taken from the recreation that I used in an aggravated assault case. The computer recreation demonstrates how:
(1) defendant looked in the window of girlfriendís house, (2) girlfriend called to defendant from across the street, (3) defendant turned to face girl, (4) assailant attacked defendant from behind, (5) assailant began hitting defendant who was on hands and knees, (6) assailant continued striking defendant for 10 seconds, (7) defendant knocked assailant off his back, and (8) shot fired at assailant in self defense .










Computer recreations and simulations can be effectively used as evidence to (1) illustrate a key defense witnessesÌ testimony, (2) to illustrate a set of complex facts, and (3) to illustrate an expertÌs testimony. Admissibility into evidence will be determined by whether the recreation is offered as scientific evidence (computer simulation) or demonstrative evidence (computer recreation).

The admissibility of demonstrative evidence is within the sound discretion of the trial court. The trial judge must determine whether the evidence is relevant to any material issue in the case and whether its probative value outweighs any prejudicial effect it might have. In federal court, to gain admission of a computer recreation as demonstrative evidence, the attorney must satisfy the relevancy requirements of Rules 401 and 402 Fed.R.Evid. Rule 401 provides that Ïrelevant evidenceÓ means evidence having any tendency to make the existence of any fact that is of consequence to the determination of the action more probable or less probable than it would be without the evidence. In other words, counsel must show that the recreation tends to make the existence of any material fact more or less probable than it would be without the evidence. Rule 402 provides a presumption that all relevant evidence is admissible unless otherwise prohibited.

A computer simulation is scientific evidence. Defense counsel should establish the authenticity of the computer generated simulation pursuant to Rule 901(a) Fed.R.Evid. The sponsoring witness should be prepared to testify as to the reliability of the procedure used to produce the simulation and the resulting accuracy of the graphic images. Rule 702 Fed.R.Evid. governs the admissibility of all expert testimony in federal court. The United States Supreme Court in Daubert v. Merrell Dow Pharmaceuticals, 113 S.Ct. 2786, 125 L.Ed.2d 469, 61 USLW 4805 (1992) overruled Frye v. United States and held that: (1) Ïgeneral acceptanceÓ is not necessary precondition to admissibility of scientific evidence under Rule 702 of the Federal Rules of Evidence, and (2) Rules assign to trial judge the task of ensuring that expertÌs testimony both rests on reliable foundation and is relevant to task at hand. The initial determination for the trial court under Rule 702 is whether the expertÌs testimony is reliable. If the court determines the evidence is reliable (thus probative and relevant) then it must determine if the proffered testimony and computer graphics will help the trier of fact understand the evidence or determine a fact in issue. Once the animation or simulation has met the authentication and relevancy standards, its probative value will be self-evident.

Computer simulations based on a scientific theory must satisfy three criteria to be considered reliable:

(1) the underlying scientific theory must be valid;
(2) the technique applying the theory must be valid; and
(3) the technique must have been properly applied on the occasion in question.#


If you decide that a computer generated forensic recreation or simulation would be beneficial to your clientÌs case, I have the following practical suggestions:

(1) I believe that a professional animator should be employed to prepare a forensic recreation. Creation of the recreations requires special skills to insure accuracy and to maximize visual impact.

(2) Provide the animator with witness statements, photographs, relevant documents, and any additional material available that can support the recreation. For example recordings of police radio transmissions or emergency telephone calls may precisely fix the timing and sequence of depicted events. Photographs, charts, diagrams, accident reports, and medical records can also be helpful.

(3) The attorney and client need to work very closely with the animator. Attention to every detail is essential to an accurate and admissible presentation. By monitoring the production of the recreation you can avoid costly mistakes that can cause a particular graphic image to be redrawn. For example, in my case the original graphics depicted the defendant too close to the window of the house. This subtle mistake required a time consuming and somewhat costly reconstruction of that particular scene.

(4) I particularly like the technique of showing an actual photograph of an object such as a house or automobile and then slowly fading from the photograph to the computer generated graphic representation of the same object. I feel this clearly demonstrates to the court and jury the accuracy of the recreationÌs images.

(5) You should seriously consider preparing a Notice of Intent To Use And Request For Pretrial Ruling On Admissibility of Use of Computerized Video Simulation Entitled State v. John Doe As Demonstrative Evidence At Trial. You should make a copy of the simulation/recreation available to the prosecution upon request and thus comply with the reciprocal discovery provisions of Rule 16(b)(1) Fed.R.Crim.P. or the state counterpart.#


















Defendant hereby respectfully requests that the Court order that he be permitted to utilize a videotaped computer generated recreation entitled State v. Defendant as demonstrative evidence at trial. In support of this Motion, the Defendant would show the following:

1. The videotape is a computer-developed visual representation of the sequence of events surrounding the alleged aggravated assault on complainant on or about July 5, 1996.

2. The computer generated recreation was produced by JuriLink, Inc. of Dallas, Texas under the direction of Brian Harston.

3. The videotape of this recreation was given to counsel for the prosecution on September 30, 1996. The facts and data relied upon by JuriLink to produce the recreation are noted in Exhibits A and B and have also been previously supplied to the prosecution.

4. In People v. McHugh, N.Y. Appt., 476 N.Y.S.2d 721 (1984), the defendant in a criminal case sought admission into evidence at trial of a computer generated recreation of an automobile accident which demonstrated and supported the opinion of his accident reconstruction expert. The trial court admitted the recreation into evidence at trial, noting Ïthe evidence . . . is akin to a chart or diagram. Whether a diagram is hand drawn or . . . drawn by means of a computer is of no importance.Ó Id. at 722-23. Mr. Harston, expert witness for the defendant, will testify that the video recreation in this case is nothing more than a hi-tech version of the carts and graphs normally relied on by experts at trial.

5. All relevant evidence is admissible. Texas Rules of Criminal Evidence Rule 402. If the Court deems that the video recreation is relevant, and that its admission will not result in unfair prejudice, confusion of the issues, or misleading the jury, it should be admitted into evidence during the trial of this case.
6. The expert responsible for the creation of the video recreation, has stated his attached affidavit [Exhibit 1] that the video was created using equations of motion, computer software, and computer hardware which have wide acceptance in the relevant scientific community.

7. The video tape was developed using widely accepted techniques and is a visual aid to help the jury understand the sequence of events surrounding this case from the DefendantÌs perspective. The computer generated recreation is demonstrative evidence which should be admitted into evidence to assist the jury in its role as fact-finder.

Defendant respectfully requests that the Court permit the admission of the computer generated video recreation into evidence. Defendant prays that this Motion in all things be granted by the Court.

Respectfully submitted,

E. X. Martin, III
Attorney for Defendant
State Bar # 13114500
8828 Greenville Avenue
Dallas, Texas 75243
(214) 3437400


The foregoing Motion is set for a hearing on the day of , at ___________oÌclock, A.M.


Computer Generated Demonstrative Evidence
Created On Your Own PC
Street Atlas USA Version 4.0JA

Graphic sa1.gif

I was able to prepare an accurate map depicting the location of the shooting and location of the house where the defendantÌs friend lived in a matter of minutes. This map was important because the defendantÌs friend took photographs of him shortly after he arrived which established the injuries inflicted and the severity of the beating. I also wanted to blunt any contention by the prosecution that the defendantÌs injuries were not severe enough to keep him from seeing to drive an automobile. I prepared the map using a software program called Street Atlas II USAJA. This program is on one CD-ROM disk and contains every street in the United States. You can locate a street by name and obtain close-up or distant views of the selected area. To prepare the my exhibit, I started the program and found the area where the womanÌs house was located. I then saved this map to a computer file and printed it out on an HP 855 C color printer. I was able to produce this piece of demonstrative in a matter of minutes. The following screen snapshots depict the software program interface and the map that I prepared for the trial.

Grpahic sa2.gif

Graphic sa3.gif

I annotated the above exhibit using the Windows 95 Paint program. I added the text boxes ÏShooting LocationÓ and ÏFriend's HouseÓ . I often use Street Atlas to make demonstrative evidence exhibits. I have a Hewlett Packard color printer that I use to print out the map exhibits.


The WordPerfect7A Tables feature can help you produce inexpensive and effective exhibits on your office computer. This feature can be used to produce demonstrative evidence for jury trials and motions. I used a table in the assault case to demonstrate to a jury contradictions and inconsistencies in the complainantÌs testimony. This table or chart was prepared using WordPerfect7A and was printed on my laser printer and then blown up for use in final argument. It only takes a few minutes to make the chart and print it. The chart was a valuable tool in destroying the complainantÌs credibility.



Court Test.
Court Test.

Hitting Woman


Drinking Alcohol




Strike Defendant
Before Shot

Many Times
Fought with Defendant over pistol

Def. Bleeding
When Shot Fired


Prior Conviction

Assault on Female

Maps, charts, figures, and graphs are also easily produced using computer technology and software. This type of evidence can help both criminal defense lawyers and civil law practitioners for both motion practice and trial.


There are several new software programs that can be used to add impact to photographs that you want to use as evidentiary exhibits in a trial. The programs are inexpensive and easy to use. I have been using a program called MGI PhotoSuite. I like this program because it has several special tools that can be used to work with photographs. I paid approximately $ 50 for the program.

Graphic mg1.gif

The PhotoSuite interface is depicted below.

I added text to the photograph below using the PhotoSuite program. The inscription ìA life is only important in the impact it has on othersî is the inscription on Jackie Robinsonís tombstone. In the future I will use this software to add text to photographs I intend to use in a trial. I think the addition of text to a photograph could add desired impact to a particular photograph.

Graphic mike2.gif



There are several software pagckages that can be used to graph or chart various forms of data. These graphs can be very powerfur exhibits during a trial. The figure below is a graphic I prepared using Excell to support my Motion To Dismiss Indictment for Vindictive Prosecution. The graph reflects the higher punishment exposure my client faced in a 2nd indictment that was filed after the client rejected a plea bargain.

Figure vingraph.gif

I have seen very effective graphs used in divorce cases to reflect earning potential of a spouse as compared to the other spouse.
# See People v. McHugh, 476 N.Y.S.2d 721 (N.Y. Sup. Ct. 1984). The New York Supreme Court stated, Ï[C]omputers are simply mechanical tools - receiving information and acting on instructions at lightning speed. When the results are useful, they should be accepted; when confusing, they should be rejected. What is important is that the presentation be relevant to a possible defense, that it fairly and accurately reflect the oral testimony offered and that it be an aid to the juryÌs understanding of the issue.
# See P. Giannelli & E. Imwinkelried, Scientific Evidence § 1-1 (1986).
# It is advisable to give notice to the prosecution and have a hearing on the admissibility of this evidence prior to trial. See Stephens v. Miller (7th Cir. 1993), 989 F2d 264.

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