Lecture 9 - Blood spatter analysis

Question 1

What are the cohesive properties of blood?

Answer 1

The formation of blood droplets in flights

Question 2

What are the adhesive properties of blood?

Answer 2

The formation of bloodstains

Question 3

What type of blood cells has no nucleus or DNA?

Answer 3

Red blood cell

Question 4

What type of blood cell is targeted for screening test?

Answer 4

Red blood cell due to the presence of the haem molecule

Question 5

What type of blood cell is targeted for DNA analysis?

Answer 5

White blood cells due to the presence of a nucleus and DNA

Question 6

What is involved in the Hemastix presumptive blood test?

Answer 6

Test strip containing TMB is rubbed against suspected stain with a drop of sterile water. Positive results gives a green colour reaction

Question 7

What is involved in the Kastle Meyer presumptive blood test?

Answer 7

Swab with phenolphthalein is rubbed against suspected stain with ethyl alcohol and hydrogen peroxide. Positive results gives a pink colour reaction as haem reacts.

Question 8

What is involved in the immunochromatographic assay confirmation blood test?

Answer 8

Employs an antibody-antigen-antibody sandwhich method using antibodies that recognise human hemoglobin

Question 9

What blood enhancer produces a chemiluminescent product?

Answer 9

Luminol

Question 10

What blood enhancer produces a fluorescent product?

Answer 10

Hemascein

Question 11

What blood enhancer produces a dark blue or black product?

Answer 11

Amido black

Question 12

What blood enhancer produces a blue/green product?

Answer 12

Leuco malachite green

Question 13

What are the steps of blood droplet formation?

Answer 13

Sheet - lattice - ligaments - beading - droplets

Question 14

Passive bloodstain

Answer 14

Formed with gravity acting as the main force produces drip and flow patterns and pooling of blood.

Question 15

Spatter bloodstain

Answer 15

Formed with an additional force acting on the blood source. Droplets are propelled through the air, dispersing into smaller drops

Question 16

Transfer bloodstain

Answer 16

Formed from contact between a blood-bearing surface and another. Either through compression or lateral movement of the surfaces

Question 17

Altered bloodstain

Answer 17

Formed with characteristics indicating a physical or physiological changes

Question 18

Cast off bloodstain

Answer 18

Resulting from blood being projected in motion

Question 19

Arterial bloodstain

Answer 19

Resulting from blood spurting from wound

Question 20

Fly blood spots

Answer 20

Resulting from fly activity transferring blood

Question 21

Void bloodstain

Answer 21

Resulting from a secondary object coming between blood spatter and final target

Question 22

What is used to measure a bloodstain?

Answer 22

Microscopic lense with scale

Question 23

What bloodstain feature is determined through 2D representation?

Answer 23

Area of convergence

Question 24

What bloodstain feature is determined through 3D representation?

Answer 24

Region of origin

Question 25

What do the letters of blood types indicate?

Answer 25

Antigens on the surface of red blood cells and the corresponding antibodies in the plasma