The way that they know that someone has been killed in one place and transported to another is by analyzing the lividity (i.e., discoloration of the skin caused by pooling of blood in the lowest parts of the body after death). and blanching of the skin at the points of contact with whatever was underneath them. When someone dies in one place and lies in that position for a period of time, and is then transported to another location and is put there in a different position, then there are two separate patterns of lividity and blanching. There might have even been a third pattern for the time that she was transported. The person would have had to have been dead in the first position for a while for the first lividity pattern to form. The authorities probably know whether her initial position was face down, on her side, or on her back. If she was placed in the trunk of a car (most likely in a fetal position), she probably would have had the lividity and blanching on her side. If she was transported in a seated position in the passenger seat, the patterns would be seen in her feet and buttocks. Transportation by motorcycle or horse would probably produce a very strange lividity and blanching pattern.