An evaluation of human stabbing performance to inform the standardisation of textile damage examinations: Do simulation trials correlate to reported stabbings?

Abstract

Forensic textile damage examinations are commonly requested in cases such as stabbings. These requests often involve the testing of knives or other weapons submitted to determine if they could have caused the damage to the evidential garment. Currently a forensic practitioner conducts this testing by manually performing the stabbing action. A biomechanics performance trial was conducted to evaluate how a range of human factors contribute to the creation of textile damage by stabbing actions. Surveys of sharp force fatalities and clinical penetrative injuries reported the chest and abdomen as the most frequent target location for stab wounds. The location of the cut-type damage recorded during the trial was found to correlate to the location of stab injuries incurred during actual stabbing cases. The type of weapon had an impact on the actions undertaken. Participants mostly utilised the smaller utility and hunting knives in underarm thrusting or overarm hacking actions, whereas an overarm hacking action, or combined hacking/slashing action was performed when using the machete. The familiarity of the knife, shape of the handle and perceived risk of injury determined how the handle was held. Participants frequently stabbed into the target immediately in front of their dominant hand, however care should be taken in interpreting this in a casework scenario. The machete was used with the highest mean velocity, and the utility knife the lowest.