Stabbing in the United Kingdom, as in many European countries is the most frequent cause of homicidal deaths. A frequent question presented to an investigating pathologist is to give the jury an appreciation of how much force, and therefore what degree of intent was used to produce a given injury. Currently, the pathologist will give a subjective opinion based on knowledge drawn upon from experience. This thesis reports on a study that has been undertaken to scientifically quantify the forces required to produce homicidal stab wounds thus removing the subjective nature of the investigating pathologist.

The study was broken down into three main categories that affect the force required to produce a stab wound and hence the degree of intent needed to inflict the wound. These three categories were the sharpness of the weapon or the stabbing implement, the resistive response to penetration of the tissue and the ability of an individual to inflict a wound.

Three methods of quantifying sharpness were developed based on knife tip surface area, penetrative resistance of a standard material and rate of change of work done with respect to time when penetrating a standard material. The three methods disadvantages. were compared for their relative advantages and Sharpness quantification as a function of knife tip surface area was found to be the most precise method.

The resistive forces to penetration of various human cadaveric tissues was measured using electronic instrumentation of a range of knife blades. The peak resistive force encountered for soft tissues was found to be 75N for penetration of skin tissue. The peak resistive force encountered for hard tissues was found to be 260N for penetration of sternum.

A kinetic analysis of the ability of an individual to inflict a stab wound was undertaken. The human stabbing performance was assessed by conducting a trial to replicate various scenarios as often described in the statement of an accused assailant.

The results for the human tissue penetration experiments were compared with the results from the kinetic analysis. This allowed a method of verification or discreditation based on whether penetration would occur in relation to the scenario described by the accused assailant.

A case study is presented in which the techniques developed in the study were used in a homicidal murder inquiry where the results were presented to a jury in a court of law.