Case Study 7: Forensic DNA

Case Study 7: DNA

Situation…

The defendant had been involved in a fight with another male. The complainant stated that he was talking to someone else when the defendant grabbed his head with both hands and bit off part of his ear. A ‘scenes of crime’ officer arrived shortly after the incident, he took photographs and recovered blood and the ear lobe from the scene. The ear lobe was sent for forensic examination.

Action…

Bericon Forensics was asked to undertake forensic testing on the earlobe for the presence of the defendant’s DNA.

Result…

We agreed with the prosecution that the defendant was a possible contributor to the low level part of the mixed DNA profile that was obtained but as the minor DNA was low level it was not suitable for robust statistical evaluation using traditional methods.

We concluded that it was not possible to determine when or how the DNA had been deposited and suggested there may have been other mechanisms by which DNA from the defendant could have transferred to the ear if someone else had bitten it off and failed to deposit detectable amounts of their DNA.

The CPS offered no evidence.