Bloodstain Directionality
A bloodstain will point in the direction of travel. The stain above indicates it was traveling from left to right. There is, however, an exception to this when discussing a wave cast-off stain. Notice that the tail separated forming a wave cast-off stain which points back towards the parent stain. The following pictures are presented to demonstrate a blood trail. It is not unusual to find blood trails at crime scenes; therefore, it is important that we recognize them and be able to determine (if possible) the direction of travel. Some stains are more obvious in their direction of travel (like the one above) than others that are less elliptical. The following pictures display an injured woman walking and running.
Victim or Suspect Walking
A few things that we know are for certain, is that gravity and air resistance are always at work on a blood drop in flight. Additionally, we know that with the forward momentum of this woman, whether walking or running, the blood drops do not drop straight down to the Earth but in these cases will follow along with the direction of her travel; thus, hitting the surface at a more acute angle. Walking tends to put the drops closer in proximity to each other than running due to the difference in speed; however, it appears to me that caution would be used here due to not knowing the rate of bleeding and/or hemorrhaging. Finding more spherical (closer to 90 deg) stains along a blood trail would indicate a slowing or pause in travel, i.e., standing in place.
Victim or Suspect Running
Picture's created with Poser 8 ® and enhanced with Microsoft Paint ®