State v Swinton Sets New Guidelines for Computerized Evidence
Do you or your experts use computerized evidence? If so, you'll want to be sure they know about and follow the guidelines in this ruling.
As with Porter, the May 3 decision in State v. Alfred Swinton, which upheld Swinton's murder conviction, is expected to extend far beyond the case that spawned it.
In March 2001, Swinton was found guilty of the January 1991 murder of 28-year-old Carla Terry in Hartford. Carla's body was found in a snow bank, partially clothed and wrapped in a brown garbage bag. Several crescent shaped bruises, identified as bite marks were found on her breast.
By March 1991, Swinton had become the prime suspect. During a search of his home, police found a black bra, identified as Carla's. Police also made a mold of Swinton's teeth to match to the bite marks. He was arrested, but a judge dismissed the case at a probable cause hearing.
In 1998, Swinton was re-arrested, in large part because he had made a number of incriminating statements, including one to a reporter during an interview to proclaim his innocence, but also because new scientific methods gave further credence to investigators attempting to link Swinton to the bite marks found on the victim.
At trial, two pieces of computerized evidence proved crucial to linking Swinton to the bite marks: computer-enhanced digital photographs of a bite mark on the victim's breast, and an overlay of the bite marks.
Two experts testified about the computer evidence. The first, Major Timothy Palmbach, of the Department of Public Safety's Division of Scientific Services, testified to the process of enhancing the pictures of the bite mark using so-called "LUCIS" software. (LUCIS image processing software uses a differential hysteresis processing algorithm to make detail in the highlights and shadows more visible. Similar results can be achieved using other image processing tools such as Adobe Photoshop.) The second, forensic odontologist Constantine Karazulas, claimed the bite marks were a match with Swinton's teeth. Karazulas, however, could not testify to the procedure used by the technician who created the overlay of the bite photos and the scanned image of the teeth mold.
More than 20 pages of the Supreme Court's 54-page decision, penned by Justice Joette Katz, focus on the two pieces of computerized evidence.
The state claimed the computer technology was simply presenting the evidence to jurors, similar to using a PowerPoint demonstration. The defense argued the computer technology altered the original images and therefore the technology's reliability needed to be established.
The new standard set by the decision builds on the 25-year-old ruling in American Oil v. Valenti that adopted rules of federal procedure to establish foundation. Those rules require testimony to establish:
- The computer utilized is accepted in the field as standard, competent and in good working order;
- Qualified operators, proper procedures and reliable software programs were employed;
- The equipment was programmed and operated correctly; and
- The exhibit is properly identified as the output in question.
"As in our decision in Porter, we stress that these factors represent an approach to the admissibility of computer generated evidence, and not a mechanical, clearly defined test with a finite list of factors to be considered," Katz wrote. "...Moreover we note that, because the domain of computer generated evidence expands on a nearly daily basis, by the time we could make a ruling regarding one particular program or application, that program would become obsolete and a new one would take its place," Katz noted. "We do not wish to enunciate a standard that is applicable today and useless tomorrow."
How can you be sure that computer evidence you plan to use passes the test? ... Make sure your experts use an archive history file.
What's an archive history file? It's a document that answers the rules set forth by this ruling and allows any competent outside party to verify the results and the process to achieve them.
I developed the process of an archive history file several years ago to answer potential challenges to geographic evidence (scientific or demonstrative) that our firm provides for use in a legal matter. You might find a food analogy helpful to understand what an archive history file is.
Suppose you had dinner at a friend's home and it was so wonderful that you wanted to be able to duplicate it exactly. To do so, you'd need three things: a detailed list of ingredients; a detailed list of tools (mixer, oven, etc.); and, a detailed recipe (a narrative documenting how the tools were used to modify the ingredients).
In the same way, if you or opposing counsel wants to duplicate, or check the veracity of a computer generated or presented exhibit, you'd need an archive history file. A document that details exactly the raw ingredients, the tools used, and the recipe specifying what was done to reach the end result.
In the case of a computer-generated map showing locations of plaintiffs, soot and toxic gas clouds overlaid on top of an aerial photograph, you'd need the following:
- Ingredient list - what images were used, where they came from, how and when they were ordered; what source data was used to locate the claimants such as their street address fro m claim forms, what streets reference file was used, where it came from and so on.
- Tools list - what computers (model and serial number, operating system, specifications, etc.) and other tools were used (scanners, plotters, stereo plotters, etc.).
- Process and methods narrative (the recipe) - this describes how the ingredients were obtained, handled, stored, ingested, operated on, and so on.
On a maritime incident case, opposing counsel took our archive history file, then hired an independent geographic information firm to duplicate our work. I suppose they hoped to find flaws that would discredit the exhibits. Instead they spent significant resources rushing to duplicate our analysis only to discover that the exhibits were accurate and a fair representation of the case facts and data.
Without an archive history file, they might have been able to cast doubt on our analysis and exhibits. The success of this case hinged on these computer-generated exhibits.
Call or email today if you want the 3 page Archive History File Implementation Guide.
