The significance is they can tell exactly how someone was killed by the patterns of blood with in the crime scene. It’s key in finding the murder weapon, helps find suspect even. At least narrows things down. and even cause of death. They can tell if it was a gun shot close range or far range. They can tell if it was a stab wound, if it was a bleeding out, if they were hit with a blunt object. The patterns for each of these are very specific and hard to determine sometimes, but is a HUGE factor in solving any crime.
