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Blood Spatter Lab. Blood spatter from a sneeze from a bloody nose.
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Blood Spatter Lab Blood spatter from a sneeze from a bloody nose
A couple decided to commit suicide after going through a hard time so they decided to jump off of a building together. When they got to the top they both counted to 3. The woman jumped but the man stayed behind. He watched the woman fall for 8 seconds, then saw her pull a string to a parachute she had hidden under her clothing. Who betrayed who?
“Remember… it’s blood ‘Spatter’ not blood SpLatter.”
Blood Drop blood spatter animations
Eccentricity: of an ellipse is the ratio of the distance between the foci to the length of the major axis; this is necessarily between 0 and 1. If the ellipse has the Cartesian equation
Basically “eccentricity” is how “oval” and ellipse is…. Which one is most “eccentric?”
Impact angle = sin-1(arcsin) width (d) length (D)
drop on left: W = 1.8 cm L = 2.8 cm Impact angle = sin-1 (arcsin) width length = sin-1 (arcsin) 1.8 cm 2.8 cm = sin-1 (arcsin) (0.643) = 40 degrees
drop on right: W = 1.2 cm L = 5.23 cm Impact angle = sin-1 (arcsin) width length = sin-1 (arcsin) 1.2 cm 5.23 cm = sin-1 (arcsin) (0.229) = 13 degrees
Formula for Table 1 Angle of Impact Impact angle = sin-1(arcsin) width length ¼” = one foot on diagram on your answer sheet Formula for Table 2 Height above point of target XY = tan(i) x XJ, angle i being the angle of impact from the previous data table
Blood Spatter Alteration of bloodstain over time • Blood dries and clots over time. • Difficult to estimate the time the blood exited the body. • Clotted smears can indicate time of movement
Blood Spatter Determining Direction of Blood • The angle can be determined mathematically. • Width/Length, then take the inverse sin (sin-1). • This number is the impact angle (90 = perpendicular to surface; <10 at a sharp angle)