Photography and Digital Imagery
Dave Carlson - September 1, 2006
Since the invention of photography, forensic investigators have been using images to document crime scenes and evidence. Unfortunately, immediately on the heels of the invention of photography, came the invention of trick photography. With the advent of digital cameras, camera tricks became as easy as a click of a mouse button.
Digital imagery has morphed into computer animation and simulation. Fiedler (2003) identifies this technology when used in a courtroom as “computer generated evidence (CGE)” (p. 295). She observed that “computer animation and simulation can allow attorneys to transform testimony and data into dynamic visual demonstrations, virtually transporting the jury to a re-enacted scene” (p. 295). Fiedler (2003) cautions that, even though CGE has been admitted to courtrooms for about 25 years, “judges sometimes admit it without paying sufficient attention to the pitfalls” (p. 296).
An example of the amazing use of CGE technology is a procedure called, “Virtopsy—a bloodless and minimally invasive virtual autopsy procedure to examine bodies for causes of death” (National Library of Medicine, 2006, ¶ 1). Its purpose “is to establish an observer independent, objective and reproducible forensic assessment method using modern imaging technology, eventually leading to minimally invasive ‘virtual’ forensic autopsy” (Institute of Forensic Medicine, 2006, ¶ 1).
Computers are able to approximate events surrounding an injury, as demonstrated in Figure 1. In 2003, Scientists from the Institute of Forensic Medicine collaborated with police to use 3-D imaging technology to solve a triple homicide (National Library of Medicine, 2006). They recreated a bite sequence to prove that a suspect’s teeth had created a mark on a victim’s shoulder. The jury found the simulation credible and convicted the defendant of murder.
Figure 1. Computer reconstruction of bite mark.
Institute of Forensic Medicine, University of Bern
(National Library of Medicine, 2006).
Fiedler (2003) defines two forms of CGE: computer animation and computer simulation. Animations use a series of images and play them back in rapid succession the same way a movie film portrays a scene. A simulation presents images based on computer algorithms that comply with laws of science and physics (p. 297).
To be admitted as evidence, computer animations must be “faithful reproductions of the object or thing being depicted.” Additionally, they must “clarify or illustrate relevant events in the case or provide useful background information” and include testimony from the expert who developed the animation that it is both valid and accurate. “Further, both the source information and the computer processes used to create the animation are subject to judicial scrutiny for their reliability and accuracy” (Fiedler, 2003, p. 298).
A significant downside for using computer animations as evidence is that “the jury may view the animation only when the expert testifying uses the animation to illustrate their testimony.” The testifying witness also must “state that the CGE portrays the disputed subject matter fairly and accurately” (Fiedler, 2003, p. 299). Fiedler concludes this section of the article by describing at least six methods where a judge can disallow animations as evidence (Fiedler, 2003, p. 301).
Fiedler warns of the dangers of animation. Animated displays can keep the jury’s attention and make complicated technical issues understandable, as well as present realistic and powerful images. However, the jury “may be misled by forceful visual reconstructions of complex events” (Fiedler, 2003, p. 302). Fiedler (2003) concludes with a discussion of psychological research that indicates jurors may ignore the laws of physics and “place great weight on a computer generated display that makes this information accessible, understandable and non-intimidating” (p. 303). She implies, based on the findings of at least two experts in social psychology, that it is easy for jurors to suspend disbelief when they view a computer animation, because of the pervasive nature of miraculous happenings in television movies (Fiedler, 2003, p. 307).
Fiedler (2003) discusses ways an animation can meet the rules of evidence, yet “violate reality” (p. 314). She uses an example of where an animation flies the jury about the crime scene and related events from angles and positions not humanly possible. Fiedler (2003) describes traveling “just behind and above the speeding truck” or having an underground view (p. 314).
Fiedler (2003) concludes that “use of CGE is bound to increase in the near future” and predicts that further research on CGE and the application of “appropriate rules and guidelines, there is no reason why CGE cannot become an integral and effective tool for presenting evidence in the courtroom” (p. 321). However, she cautions that “technology is subtle” and “deceptive computer tactics are not well understood by the legal community” (p. 321). “By applying social science principles, technology can be controlled and harnessed to assist in the pursuit of justice” (Fiedler, 2003, p. 321).
Fiedler, B. S. (2003). Are your eyes deceiving you?: The evidentiary crisis regarding the admissibility of computer generated evidence. [Electronic version]. New York Law School Law Review, 48(1), 295-322. Retrieved September1, 2006, from http://www.nyls.edu/pdfs/v48n1-2p295-322.pdf
Institute of Forensic Medicine. (2006). Virtopsy. Retrieved September 1, 2006, from http://www.virtopsy.com
National Library of Medicine. (2006). Virtopsy: The virtual autopsy. Retrieved September 1, 2006, from http://www.nlm.nih.gov/visibleproofs/galleries/technologies/virtopsy.html