This experimental study investigates the parameters controlling the spatial distribution and size distribution of blood spatter stains. An experimental setup consisting of two cylinders colliding along their main axis is used to produce spatter patterns, under conditions where the impact velocity and kinetic energy of the impact are independently controlled. The resulting spatter patterns are scanned and made available as digital images. Characteristic distributions of stain sizes and stain positions, as well as the number of stains, are measured. The influence of the velocity and kinetic energy of the impact, as well as the shape of the impactor, is quantified and interpreted. An energy analysis is performed and provides a criterion based on dimensionless parameters to determine which impact conditions influence the spatter pattern. High-resolution images of the 19 spatter patterns produced during the study are made available in an open-access repository.