Term
| How much blood do you need to lose to die from blood loss? |
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Definition
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Term
| How much blood does the average male have in his body? |
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Definition
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Term
| How much blood does the average female have in her body? |
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Definition
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Term
| Define Bloodstain Pattern Analysis |
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Definition
| It is the examination of the shapes, locations, and distribution patterns of bloodstains, in order to provide an interpretation of the physical events that occurred at the crime scene |
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Term
| In BPA, what is the target surface? |
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Definition
| Any surface that blood comes into contact with |
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Term
| What can blood stain analysis tell us? |
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Definition
| Direction of travel of the blood; distance of blood source to target surface; angle of impact of blood droplet; Determination of blood trail, their direction, and relative speed of motion; nature of the object used to cause the bloodshed, the number of blows involved, and relative location of persons and objects; sequencing of multiple blows; position of a victim during the fatal impact; corroborate or refute statements; establish order of certain events; determine blood collection sites for DNA |
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Term
| Define Cohesive Forces in BPA |
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Definition
| The attraction of like molecules to remain together as a unit |
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Term
| Define surface tension for BPA |
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Definition
| The cohesive forces that cause a fluid to remain in the form of a sphere. |
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Term
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Definition
| The resistance of a fluid to flow freely. |
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Term
| What is the difference in viscosity between water and blood? |
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Definition
| Blood is 3-6 times greater than water |
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Term
| The [blank] the force, the [blank] the droplets |
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Definition
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Term
| larger drops travel [blank] |
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Definition
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Term
| What causes blood to break apart? |
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Definition
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Term
| With increased distance, what will happen to the diameter of the drop stain? |
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Definition
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Term
| Diameter of drop will [blank] with [blank] distance |
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Definition
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Term
| What shape does blood travel through air in? |
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Definition
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Term
| As the angle of impact decreases, what happens to the stain? |
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Definition
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Term
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Definition
| angle at which the blood drop hits the target surface |
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Term
| What dimensions are used to determine the angle of impact? |
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Definition
| Length and width of stain |
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Term
| textured target surfaces will affect [blank] and [blank] of drop |
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Definition
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Term
| Which end of the stain tells the directionality? |
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Definition
| The tail of the drop points to the direction of travel |
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Term
| If there is no tail, how does one determine the directionality of the stain? |
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Definition
| Look for the greatest edge of disruption |
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Term
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Definition
| where a smaller droplet is cast from a parent drop at impact |
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Term
| Name the types of bloodstain patterns |
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Definition
| Drip stain, impact, projected stain, expirated, cast-off, arterial spurting / gushing, transfer, swipe, wipe |
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Term
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Definition
| A bloodstain resulting from a falling drop that formed due to gravity, forms a generally circular stain |
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Term
| Describe impact bloodstain patterns |
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Definition
| A bloodstain pattern resulting from an object striking liquid blood. Forms a pattern where the stains radiate outward |
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Term
| What causes a projected bloodstain pattern? |
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Definition
| The ejection of a volume of blood under pressure |
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Term
| What creates a cast-off pattern? |
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Definition
| blood drops are released from an object due to its motion |
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Term
| True or False: Cast-off patterns are only of the 2nd and subsequent blows. |
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Definition
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Term
| What is an expirated pattern? |
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Definition
| a pattern resulting from blood forced by airflow out the nose, mouth, or a wound |
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Term
| True or False: With a cast-off pattern you may have two directions. |
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Definition
| True, toward and away from the victim |
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Term
| What causes an arterial spurt pattern and what is it characterized by? |
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Definition
| it is blood exiting the body due to pressure from a breach artery and characterized by large volume stains; may see rise and fall like the heart beat |
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Term
| What causes a transfer pattern? |
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Definition
| caused by contact between a blood-bearing surface and another surface |
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Term
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Definition
| A stained object moves over an unstained surface. Blood transferred from a bloody object to a non bloody object with motion. |
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Term
| How do you tell directionality with a swipe pattern? |
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Definition
Look for feathered edges for directionality |
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Term
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Definition
| An altered bloodstain pattern resulting from an object moving through a pre-existing wet bloodstain |
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Term
| What is a perimeter stain? |
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Definition
| An altered stain that consists of the peripheral characteristics of the original stain. Previously known as a skeleton stain |
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Term
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Definition
| The absence of blood in an otherwise continuous bloodstain. basically something was there during the blood letting event, but since moved since the analysis |
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Term
| How do you document bloodstain patterns? |
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Definition
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Term
| What is the orientation photograph? |
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Definition
| It is the equivalent of the midrange photograph and establishes the pattern to a fixed feature |
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Term
| What is the distribution photo / pattern photo? |
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Definition
| with a scale and the lens plane parallel to the surface with blood it shows the overall pattern |
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Term
| What is the difference between a distribution photo and the close up photo? |
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Definition
| The distribution photo is of the entire pattern. The close up is of individual stains within the pattern |
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Term
| What should sketches of bloodstain patterns include? |
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Definition
| placement of the patterns, descriptions of the patterns, any measurements: dimension of the overall pattern, W and L of individual stains, Horizontal and vertical measurement of individual stains |
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Term
| What are some things that should be documented in the notes for bloodstains? |
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Definition
| environmental conditions, handedness of suspect and victim, physical description of individuals, blood on suspects and victims, color of stains, degree of dampness of stains, location of patterns, description of patterns, items collected or moved |
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Term
| What are some safety precautions when working with bloodstains? |
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Definition
| treat all blood as a possible infectious material, wear latex gloves, wear face mask, shoe protection if possible, report exposures to supervisor, no pens or pencils in mouth |
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Term
| How is area of convergence determined. |
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Definition
| By taking a ruler down the center of the stains and drawing a line till the many of the test stains converge to an area on the wall. |
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Term
| How is the angle of impact calculated? |
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Definition
| Measuring the length and the width, dividing the width by the length, and then taking the inverse sine. plus or minus 5 degree error okay. |
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Term
| What is the area of origin |
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Definition
| it is the point of impact in the 3rd Dimension calculated with the angle of impact, stringing, and the area of convergence |
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Term
| What is the area of convergence? |
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Definition
| It is the point in 2 dimensions where the stains converge, measured through the long axis of the stain. |
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Term
| In shooting trajectory what shapes of holes may you see? |
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Definition
| Circular, oval, non-descript, rectangular |
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Term
| What does a circular hole indicate? |
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Definition
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Term
| What does an oval bullet hole indicate? |
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Definition
| impact angle less than 90 degrees |
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Term
| What does a non-descript bullet hole indicate? |
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Definition
| impact angle made by a damaged projectile |
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Term
| What does a rectangular bullet hole indicate? |
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Definition
| Impact angle made by a tumbling projectile |
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Term
| True or False: You must have at least two defects to determine the angles. |
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Definition
| True, otherwise the dowel could be at any angle |
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