Determining the cause of an injury and the force behind the impact may be of crucial importance in a court case. For non-penetrating soft tissue injuries there is a lack of information available in the literature. In this study controlled bruises were inflicted on an anesthetized pig by high speed, low-weight paintball projectiles (diameter 17.1 mm, weight 3.15 g). The speed of the object and the impact itself were monitored using a high speed camera. Punch biopsies (5 mm) were collected from the injury sites. A red and purple ring with a diameter of 1.5 cm appeared on the skin within 30 seconds after the paintball impact. The ring was visually fully established after 5-10 minutes. Numerical finite element simulations performed with ABAQUS\Explicit showed a build up of shear stresses in the skin where the ring formed. Biopsies demonstrated severe dermal vessel damage in the same area. It is concluded that considerable shear stresses during the impact will create dermal vessel damage and thereby cause a visible bruise. Larger forces are required for compressive stresses to inflict equivalent vascular damage.