The Wisdom of Teeth: A forensic odontology workshop with Dr. Cheri Lewis
Visionary Professor Donald Johnson, in association with LAVA, Esotouric and the California Forensic Science Institute, invites you to participate in a special four-hour event at LA’s regional crime laboratory, on the campus of Cal State LA. Space is very limited and pre-reservation required for this rare opportunity to visit the Cal State LA School of Criminal Justice and Criminalistics at the Hertzberg-Davis Forensic Science Center. Learn from working forensic investigators and educators. Discover the real art and science of crime investigation.
Imagine yourself as a forensic scientist on the scene of a massive disaster, with many lives lost and the victims unrecognizable through conventional means.
Modern forensic science offers a variety of tools by which badly damaged human remains can be accurately identified, and next of kin notified. You are probably familiar with the basics of DNA-based identification, but that’s just one tool in the forensic scientist’s arsenal. In today’s seminar, you’ll get up close and personal with a fascinating and little-known identification method, as you learn how to use the unique markers on human teeth to give names to the unknown in a hands-on disaster simulation workshop.
Join Dr. Cheri Lewis for a half-day crash course in forensic odontology, a branch of forensic medicine that deals with teeth and marks left by teeth (as in identifying criminal suspects or the remains of a dead person). Dr. Lewis has worked as a forensic odontologist for several decades, and in the course of her work has developed her own hands on method (Locator System, or LS) for identifying large collections of dental remains, which used in combination with computer systems (WinID), has proven to be the fastest method of identification available to the forensic disaster response team.
For the first part of the workshop Dr. Lewis will review relevant dental terminology and introduce the methodology behind her Locator System (LS), which is predicated on the commonality between the right and left side of the mouth, and classification of dental remains into six basic categories—ranging from teeth with no fillings to no remaining teeth.
Once participants are familiar with the LS method of sorting dental remains efficiently—very much like one would sort a deck of cards into hearts, clubs, spades, and diamonds—they will be ready to begin the part of the workshop which is a very sophisticated game of concentration. This is a hands-on lab where the task of using the LS algorithm will be given over to several small groups of the attendees for sorting through postmortem files (unidentified victim’s dental fragments) and matching them up to antemortem files (possible victims’ dental records). Dr. Lewis will circulate amongst the groups providing feedback and guidance as the teams race the clock to come up with as many positive IDs as possible within sixty minutes.
The last part of the workshop will be a debrief on the interactive lab, a comparison of the LS method to the modern computer methods WinID, and how a combination of LS with a computer program is the most efficient way to work through IDing remains in a disaster.
Backstory: The history of algorithms and Computer-aided methods for ID’ing dental remains
In 1985 Colonel Lou Lorton developed the CAPMI (Computer-Assisted Postmortem Identification) system and ran a simulated disaster to test its effectiveness within Los Angeles. A year later, after the mid-air collision between Aeromexico Flight 498, a chartered DC-9 and a Piper PA-28-181 Archer over Cerritos, CAPMI was used by the forensic team.
What followed was a series of technological advances and an airline disaster which transformed the field of forensic odontology. With the release of Windows 95®, Dr. James McGivney began work on his WinID system, which came out of a general frustration with CAPMI’s DOS-based user-interface and the code base frozen when Col. Lorton left the military. Then on January 31 2000, Alaska Airlines Flight 261 experienced a fatal accident over the Pacific Ocean about 3 miles north of Anacapa Island. The two pilots, three cabin crew members, and 83 passengers on board were killed and the aircraft was destroyed. The forensic team, which included Dr. Lewis, used WinID.
What Dr. Lewis found was that WinID was not always accurate with its match recommendation giving a number of false leads. However, specialists who had culled the dental records of presumed victims were able to find matches with the fragments by playing close attention to characteristic fillings and root anatomy. At that point Dr. Lewis to begin to codify her LS system, which leveraged the pattern matching talent of dental specialists.
By 2002 Dr. Lewis began to publish research comparing computer systems and later studies compared computer systems to LS. A number of studies were conducted by her with models of 100 to 300 (simulated) victims in forensic science journals on the effectiveness of computer systems and LS-both as stand-alone methods and in conjunction with each other. By 2007 she published the last of her studies simulating a 300-victim disaster where LS was combined w/ WINiD and that proved to be the most effective for identification.