How Karnataka lab helped nail two of the accused

In the gangrape case,forensic dentists were able to link two of the accused to the crime by comparing the arrangement of their teeth

3 min readBangaloreSep 14, 2013 01:29 AM IST First published on: Sep 14, 2013 at 01:29 AM IST

For a three-year-old forensic dentistry laboratory in Karnatakas Dharwad district,the verdict in the Delhi gangrape case is a landmark one. For the first time in the history of criminal prosecution in India,dental forensics has played a key role in providing evidence leading to the death sentence.

For the Department of Forensic Odontology at the SDM College of Dental Sciences and Hospitals in Dharwad,the only recognised laboratory in the country for dental forensics,the gangrape case is its first major success in a criminal probe and a marked departure from its routine of checking on underage brides,underage workers and verifying the age of young athletes by looking at their teeth.

In the gangrape case,forensic dentists were able to link two of the accused to the crime by comparing the arrangement of their teeth with the bite marks they left on their young victim while brutalising her on the fateful night.

Head of the Forensic Odontology laboratory,Dr Ashit Acharya,who with a rare qualification in forensic dentistry from Australia set up the lab a few years ago,studied photographs of the bite marks on the victim and structure of the teeth of two of the accused to prove with some accuracy that they were involved in the crime.

The evidence turned out to be corroborative in the end.

From among the five accused I was able to state that there was reasonable certainty in the case of one accused that his dentition caused a bite mark. In the case of a second suspect,I concluded that his dentition was most probably responsible for a second bite mark. I could not link the other suspects to any of the bite marks, Dr Acharya said.

The premise of bite mark investigation is that no two persons have a similar arrangement of teeth. This dissimilarity is reflected in the bite marks. It does not have the uniqueness of fingerprints but we can conclude with a great degree of certainty, he said.

According to Dr Acharya,dental forensics though used in criminal investigations in many countries has rarely been accepted as evidence in criminal cases in India in the past because of questions over their accuracy when done at unrecognised laboratories.

One of the key things in the gangrape case,according to Dr Acharya,was the quality of photographs of the bite marks that were placed before the laboratory for comparison.

Evidence collection is best with good photographs. A good photograph can be the difference between life and death. If photography is good,we can proceed with investigation and provide appropriate report. If the photograph is not taken well,we will not be able to help, Dr Acharya said.

There are many cases where I have commented that evidence collected is not good enough for an opinion to be provided, he said.