Bloodstain pattern analysis (BPA), one of several specialties in the field of forensic science, inolves the study and analysis of bloodstains at a known or suspected violent crime scene with the goal of to helping investigators draw conclusions about the nature, timing and other details of the crime. The use of bloodstains as evidence is not new; however, the application of modern science has brought it to a higher level since the 1970s and '80s.