The idea of using blood patterns to obtain evidence of a crime was actually introduced in 1895 by a college professor in Poland. It took about sixty years before U.S. courts began allowing expert testimony in this field. Considered at first by mostly defense attorneys as voodoo science, it is now a highly respected field of study which involves many areas including computer modeling and physics.
The only thing I can remember about crime scene investigating when I was growing up were fingerprints. It has become so scientific now that I can see where many intelligent young people go into the field. If it weren't so gross I might have become a CSI. :)