Forensics Chapter 10 Bloodstain Pattern Analysis (Questions and 100% Verified Answers)

General Bloodstain Features correct answers Bloodstain pattern interpretation may uncover: The direction from which blood originated The angle at which a blood droplet struck a surface The location or position of a victim at the time a bloody wound was inflicted The movement of a bleeding individual at the crime scene The minimum number of blows that struck a bleeding victim The approximate location of an individual delivering blows that produced a bloodstain pattern Effects of Surface Texture correct answers Surface texture is of paramount importance. In general, the harder and less porous the surface, the less spatter results. Satellite Spatter correct answers Blood spatter around parent stain, with blood droplets whose pointed ends face against the direction of travel. Rough surfaces, such as a concrete floor or wood, usually result in irregularly shaped stains with serrated edges, possibly with satellite spatter. Direction and Angle of Impact correct answers The direction of travel of blood striking an object may be discerned because the pointed end of a bloodstain always faces its direction of travel. The impact angle of blood on a flat surface can be determined by measuring the degree of circular distortion. At right angles the blood drop is circular; as the angle decreases, the stain becomes elongated. Mathematically, the angle of impact can be calculated by the equation and determining the inverse of Sine A. Width of blood stain Sin A = ----------------------------- Length of blood stain Impact Bloodstain Spatter Patterns correct answers Impact spatter occurs when an object impacts a source of blood, projecting droplets of blood outward from the source. Forward Spatter correct answers Blood that travels away from the source in the same direction as the force that caused the spatter. Back Spatter correct answers Blood directed back toward the source of the force that caused the spatter. Classifying Impact Spatter correct answers Using droplet size to classify impact patterns by velocity gives investigators insight into the general nature of a crime but cannot illuminate the specific events that produced the spatter pattern. Low Velocity Spatter Drops with diameters of 4 mm or more normally produced by an applied force of up to 5 ft/sec. Medium Velocity Spatter