The Prosecution claimed there was no visible blood on the knife and argued that this was proof that Jeff must have washed the knife to rid it of incriminating fingerprint evidence. In fact, the knife was never tested for the presence of blood and it is likely it had been exposed to water from the fire-fighting effort.
The Prosecution Case
A key part of the Prosecution’s case at trial was to allege that before he went to raise the alarm, Jeff had spent up to half an hour on a whole range of things after killing his parents. The prosecution claimed one of these activities was to wash the knife used on all three family members. This was done apparently to remove all fingerprints on the knife so that the absence of Christopher’s fingerprints would not incriminate him.
The knife was found next to Christopher’s body. Reports from police and fire brigade witnesses vary as to its original location. Those first on the scene gave evidence that the knife was lying on the floor, whereas later witnesses said it was propped up against Christopher’s body. The knife was later photographed in this propped position.
Christopher was located almost directly below the part of the floor where approximately 10,000 litres of water was pumped by the fire brigade to put out the upstairs fire. The crime scene video shows his hair and body wet. It is apparent from the video that water was dripping to the lower level through the wooden floor boards, as well as down the spiral staircase, on to Christopher’s body and the floor around him. It is clear that a considerable volume of water fell on and around Christopher and the knife.
Police investigators handled the knife extensively using absorbent materials such as cloth and paper, prior to it being tested for fingerprints. A police expert explained that the material the knife handle was made of does not typically show fingerprints. He also explained that blood will run off smooth surfaces, such as the blade of a knife, relatively easily, and the residual blood leaves a very thin smear on the blade. The knife was not examined in the laboratory or tested for the presence of blood. Only one side of the knife was photographed and no close ups were taken.
Sometime before the 2000 inquest, police had destroyed almost all physical evidence from the case, including the knife, so there has been no subsequent opportunity to examine the knife for fingerprints or blood.
The lack of blood visible from a photograph of one side of the knife is inadequate to conclude there was no blood, and therefore infer that it must have been washed. However, the prosecution addressed this point to the jury, telling them that this is what must have happened.
The lack of fingerprints on the knife can be attributed to the material the handle was made of and the extensive handling by police prior to testing. The lack of blood or fingerprints on the knife is of no help in determining Jeff’s guilt or innocence.