In a question of first impression in Pennsylvania, the Supreme Court has held that computer-generated animation (CGA) may be relevant and admissible as demonstrative evidence in aid of expert testimony.
There are three basic types of evidence that are admitted into court: (1) testimonial evidence, (2) documentary evidence, and (3) demonstrative evidence. Demonstrative evidence is tendered for the purpose of rendering other evidence more comprehensible to the trier of fact. As in the admission of any other evidence, a trial court may admit demonstrative evidence whose relevance outweighs any potential prejudicial effect. The offering party must authenticate such evidence. The requirement of authentication or identification as a condition precedent to admissibility is satisfied by evidence sufficient to support a finding that the matter in question is what its proponent claims, Pa. R. Evid. 901(a). Demonstrative evidence may be authenticated by testimony from a witness who has knowledge that a matter is what it is claimed to be, Pa. R. Evid. 901(b)(1). Demonstrative evidence such as photographs, motion pictures, diagrams, and models have long been permitted to be entered into evidence provided that the demonstrative evidence fairly and accurately represents that which it purports to depict.
The overriding principle, that Bucks County criminal lawyers would know, in determining if any evidence, including demonstrative, should be admitted involves a weighing of the probative value versus prejudicial effect. The trial court must decide first if the evidence is relevant and, if so, whether its probative value outweighs its prejudicial effect. The Commonwealth of Pennsylvania defines relevant evidence as 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, Pa. R. E. 401. Relevant evidence may nevertheless be excluded if its probative value is outweighed by the danger of unfair prejudice, confusion of the issues, or misleading the jury, or by considerations of undue delay, waste of time, or needless presentation of cumulative evidence, Pa. R. Evid. 403.
In Commonwealth v. Serge, the Court set forth the conditions which must be met in order for a CGA to be admissible as demonstrative evidence.
Defendant argued on appeal that the trial court erred in admitting a computer-generated animation illustrating the Commonwealth's theory of the homicide into evidence. The CGA demonstrated the Commonwealth's argument that defendant tampered with the crime scene to stage a self-defense setting by showing the position of the victim and defendant, and the sequence, path, trajectory, and impact sites of bullets. The state supreme court held that a CGA was potentially admissible as demonstrative evidence, as long as the animation was properly authenticated, it was relevant, and its probative value outweighed the danger of unfair prejudice or confusion, as required by Pa. R. Evid. 401, 402, 403, and 901. The state supreme court held that the Commonwealth satisfied all of the foundational requirements for admitting the CGA as demonstrative evidence. Furthermore, the CGA was relevant evidence that enabled the Commonwealth experts to illustrate their opinions and educate the jury on the forensic and physical data. The alleged prejudicial effect of the CGA did not outweigh its relevance. Therefore, the appellate court held that the admission of this evidence was proper.