Bloodstain Patterns Research Paper
Module 16
Blood Stain Patterns
Blood Volume
8% of body weight
4 – 5 liters female
5 – 6 liters male
40 % blood loss usually causes death
1.5 liter blood loss can incapacitate
Blood Stain Evidence
Biblical murderer Cain
Abels blood on the ground cried out Cains guilt
Abel is the first documented murder
Cain is the first documented murderer victim
The bloodstain patterns left by falling, projected or smeared blood can be analysed by trained crime scene investigators.
Careful observation and measurement of the position and shape of bloodstains can give precise information about the direction of travel, angle of impact and the speed or velocity of the blood droplets.
Gravity
Gravity - is acting on blood (without the body's influence) as soon …show more content…
Surface tension
Surface tension is an upwards force that enables insects such as a water strider to “walk on water”.
Blood Stain Pattern
Recognition / analysis
Systematic form of analysis
Mathematical basis
Used in conjunction DNA analysis
Process of crime scene reconstruction
Blood is a fluid that makes up approximately 8% of the weight of a human body.
Females have approximately 4-5 litres while males have between 5-6 litres.
Blood is made up of cells (red blood cells and white blood cells) plus platelets in a yellowish liquid called plasma.
Plasma contains gases (oxygen, carbon dioxide) and molecules such as proteins, fats and carbohydrates (sugars).
Dr Edward Piotrowski scientist published “ Concerning the origin, shape , direction and distribution of bloodstains following head wounds caused by blows…first scientist to recognize the value of bloodstain interpretation
Experimented in 1895 with rabbits blood
First used in the 1940s for police purposes
Recognition
It may be blood but does it have significance ?
Will one droplet tell us anything ?
Passive Stains
Blood Dripping Into Blood
Blood Stain Patterns
Blood Volume
8% of body weight
4 – 5 liters female
5 – 6 liters male
40 % blood loss usually causes death
1.5 liter blood loss can incapacitate
Blood Stain Evidence
Biblical murderer Cain
Abels blood on the ground cried out Cains guilt
Abel is the first documented murder
Cain is the first documented murderer victim
The bloodstain patterns left by falling, projected or smeared blood can be analysed by trained crime scene investigators.
Careful observation and measurement of the position and shape of bloodstains can give precise information about the direction of travel, angle of impact and the speed or velocity of the blood droplets.
Gravity
Gravity - is acting on blood (without the body's influence) as soon …show more content…
Surface tension
Surface tension is an upwards force that enables insects such as a water strider to “walk on water”.
Blood Stain Pattern
Recognition / analysis
Systematic form of analysis
Mathematical basis
Used in conjunction DNA analysis
Process of crime scene reconstruction
Blood is a fluid that makes up approximately 8% of the weight of a human body.
Females have approximately 4-5 litres while males have between 5-6 litres.
Blood is made up of cells (red blood cells and white blood cells) plus platelets in a yellowish liquid called plasma.
Plasma contains gases (oxygen, carbon dioxide) and molecules such as proteins, fats and carbohydrates (sugars).
Dr Edward Piotrowski scientist published “ Concerning the origin, shape , direction and distribution of bloodstains following head wounds caused by blows…first scientist to recognize the value of bloodstain interpretation
Experimented in 1895 with rabbits blood
First used in the 1940s for police purposes
Recognition
It may be blood but does it have significance ?
Will one droplet tell us anything ?
Passive Stains
Blood Dripping Into Blood