[Influence of negative ambient temperature on the morphology of blood droplet traces]

The aim of this study was to identify the peculiarities of blood droplets on the street in frosty weather on the surfaces of objects with a negative temperature. The effect of negative ambient temperature (-19 °C) on the morphology of blood droplet traces was experimentally established. On cold trace surfaces, the droplet footprint was smaller, relatively flat and with wave-shaped edges; there was no splashing. Such a morphological presentation in frosty weather arises from the rapid cooling of the falling drop of blood which crystallizes in contact with the cold surface. There was no complete spreading of liquid droplets. The data obtained should be taken into account when assessing the traces of blood droplets detected at the scene of the incident on the street in winter, in order to avoid expert errors in determining their mechanism and the height of the blood source.