We recently had a case where the Crown expert concluded her findings provided strong support that the defendant had broken the wine glass used in an alleged assault on his partner. The Crown expert arrived at this conclusion largely because she considered the properties of the glass to be unusual and the only possible alternative explanation to be that the glass on the defendant’s clothing had come from another source entirely, which happened to match ‘purely by chance’.
Let’s consider the context:
The assault is reported to have occurred in the hall of the couple’s flat, with the defendant allegedly striking his partner twice in the face with a wine glass, causing deep cuts. The defendant did not deny that one of their wine glasses was broken. The defendant did dispute the IP’s version of the event which caused the injury and stated that following an argument he had stepped outside the flat to smoke. On seeing his partner closing the front door he pushed back hard on it in order to enter, which caused her to overbalance. He believes that his partner was holding the glass at the time and that it was either pushed into her face by the door, or she fell onto it when knocked off her feet. The location of the broken glass was not noted by the police officers who attended the incident.
Let’s consider the science:
Glass fragments were recovered from the defendant’s clothing. Given the defendant’s account, the provenance of the glass was not really in question; but how did the glass get there if he was on the wrong side of the door? Could this be explained by secondary transfer? As it happens, the defendant also stated that following the incident he moved about the flat collecting various items including shoes from behind the front door, which he held underneath his arm. Could this contact have provided a transfer mechanism? Fortuitously Keith Borer Consultants has recently carried out research in this area (Science and Justice 53 (2013) 166-170) and so our expert was confident in stating that if there had been a large population of broken glass on the shoes when the defendant picked them up, then secondary transfer could account for the Crown’s findings.
On the eve of trial, 7 weeks after our report was served, the CPS dropped charges.
Dr Guy Cooper, Forensic Chemist