Weapon Mark Matching – A Branch of Forensic Odontology

Persephone Lewin
 

Forensic odontology, an international term for forensic dentistry, falls into two broad categories. The first is the confirmation of a person’s identity from their dental records, utilised in plane crashes or a marine disaster as befell the Herald of Free Enterprise; also employed where a body has been skeletonised, burnt or decomposed.
Allied to this is the ageing of remains when  there is no clue to identity.  This narrows the search for the dental records.  Ageing is also carried out on live persons, for instance immigrant pickpockets who claim to be under age, in London’s West End.
The other side of the coin is matching injuries with the causative weapon in criminal cases.
The outline of legs on a cushion, products of decomposition; a teenage murder victim with the imprint of a button on her chin; a young man hit with a sovereign ring.  The expertise for solving such diverse cases started with bite marks.  Teeth are man’s oldest weapon.
Bite marks confirm or refute the victim’s story if he is alive.  If the victim is dead they speak on his or her behalf.  Bites fall into three categories. There are bites inflicted during sexual attacks, in fights and in child abuse and have different characteristics. Eg in sexual attacks there is often signs of sucking, surrounding by tooth marks.  This is petechial haemorrhage, an area of pin point-size red dots, commonly known as a love bite and humans are the only creatures who make this sort of mark. 
 

Occasionally bites made by animals have to be examined and here dogs are the most frequent culprits.  In 1997 a Rottweiler owned by the MP Alan Clark, bit a BBC cameraman.  The author has also matched lions’ tooth marks.
As to be expected, imprints of teeth are found in food. Tooth marks in a partly eaten apple turnover was the main evidence in a trial where the victim was an old woman of eighty seven who had been sexually assaulted and murdered.
They are also seen in such diverse objects as the fob of a key ring; the back of a watch; the end of a pencil, in fact anything that can be placed in the mouth.  But, as regards criminal investigations, they are mainly found on skin and are more common than might be supposed.
Even when all the bruising has disappeared an injury can sometimes be brought back using ultra violet light.  This doesn’t always work.  However use of a quaser light on dirty marks on the victim’s tee shirt in the case R v Jackson produced spectacular results.
The use of digital imaging in court, using Photoshop, for matching injuries is the biggest leap forward in the cause of justice of recent times.  The test case was school girl victim, Helen Gorrie, where pivotal evidence was the imprint of a jean’s button on her neck and chin.
It could be classed as the most glamorous of the medical forensic specialities in so far it often points the finger; the trial can pivot on the findings of the forensic odontologist.

Cases referred to are detailed in Bite to Byte: Crime scene to mortuary to trial - www.persephonelewin.com
 

The above image shows the ornamental jeans button. It was round with an inner circle and contained two parallel lines at the centre, which, together with the inner circle, formed two ‘D’ shapes, each enclosing a winged outline. The parallel lines enclosed the word ‘EASY’ in raised lettering and there were Roman letters and numerals between the inner circle and the rim.