Crime Scene and Specialists Flashcards
Who is first on the crime scene usually?
First Officer Attending (FOA) usually a junior level police officer
What is the job of the First Officer Attending?
Assess, protect and communicate
Seal area off
Take log of people entering and leaving
Call for senior assistance as soon as possible
What is the job of scientific job officers (SSOs)?
Check cordon (have inner cordon- vicinty of crime scene and a outer cordon- protection of inner cordon)
Assess personnel/ equipment
Photography
“Those clothes”
What do ‘stepping plates’ do?
Stops people standing (contaminating) evidence
What are the generic things officers should carry out?
Least disturbance to body Record body- number of wounds, position Record everything e.g. weather, surroundings, people Review path Placement of tent surrounding are
What is the purpose of putting up a tent at a crime scene?
Stop weather and bacterial contamination, prevents media coverage
What are the other roles required in crime scene investigations?
CSM (crime scene manager) oversee everything/ extensive crime scenes i.e. terrorism
SIO (senior investigation officer), forensic pathologist enter
Senior Investigating Officer e.g. DS/DCI
Scientific Support Supervisor
Crime Scene Manager
What is the role of the forensic pathologist?
Determine cause and manner of death
Examine wounds/injuries
Collect samples
Role as an expert witness
What are the post-mortem changes?
- Temperature Drop
- Lividity
- Rigor mortis
- Decomposition
What occurs in post-mortem regarding temperature?
Body is warmer than surrounding temperature
After death body cools to outside temperature
What slows down the cooling down process initially?
Anaerobic resporation occurs after death (bugs in gut)
What are the variables affecting temperature drop after death?
Surrounding temperature
Clothing and covering (e.g. hoodies)
Body size (fatter people body temp takes longer)
Body position (curled up longer, spread out quicker
Initial temp at death (fever at death takes longer, lost a lot of blood body temp lower quickly)
Nature of death
What occurs in post-mortem regarding lividity?
Blood drains to the lowest point of the body due to gravity (N.B. fibrinolysins- enzymes in blood stop blood clotting, stops moving blood moving around to begin with)
Pallor (paleness) at pressure point (dead on back pale back)
What variables affect lividity onset?
Things like haemorrhage and chronic anaemia
What colour is the blood if the individual has Carbon Monoxide poisoning?
Cherry pink
What occurs in post-mortem regarding rigor mortis?
Stiffening of muscles due to the breakdown of ATP to ADP
Time after death (hours)
What is decomposition?
Gradual breakdown of tissues
What are the 2 processes of decomposition?
Autolysis
Putrefaction
What is Autolysis?
Digestive enzymes eat away at itself, auto digesting
What is Putrefaction?
Process of decay or rotting the body
What do bacteria produce and cause in the decomposition process?
Produce enzymes causing gas formation from fermentation
What is a Forensic Odontologist?
Examine teeth and bitemarks
How can forensic odontologists compare teeth before and after death?
Ante-mortem vs. post-mortem data e.g. dental records
What are the age estimation in teeth?
+/- 7 years for adult
+/- 6 months for child’s
+/- days for foetus
What is the role of the forensic anthropologist?
Identify bones
What features can a forensic anthropologist identify?
Human/animal How many individuals Sex Stature Age- foetus/ child/ adult Foetus- 3 fragmented bones Child- one bone with a scar Adult- one smooth bone
What is the easiest way to ID bone?
Excavation in situ
Once bone is taken out of context, it’s harder to ID
What are the radioisotope dating options?
Carbon 14
Lead 210
Caesium 137
Polonium 210
How can Carbon 14 age bones?
In bone when alive, don’t obtain any more after death, decay can indicate age
How can Caesium 137 identify bones?
Can tell if it was post or pre nuclear testing
How can Polonium 210 identify bones?
Can tell you if death was in the last 2/3 years
Whats the main bone differences in males and females?
Bone structure of pelvis and cranium
What is the difference between a male and female pelvis?
Female pelvis is broader, wider and flatter than males
What is the difference between a male and female cranium?
Differences in skeletal and muscle attachment, males have point at the back of the head which women dont
What age group can you not distinguish sex from?
Pre-pubescent juveniles
Which bones can height be assessed from?
Long bones and refer to data to determine height
What is musculature assessed from?
Muscle insertion site
Bone robusticity
Site of joint surfaces
What does bone reconstruction show?
Allows damage to be assessed
Helps explain events
What can gunshot wounds (GSW) show?
Size of entry, wound, weapon, bullet trajectory, location, distance of perpetrator
What can blunt force trauma show?
Weapon used, number of blows
What does black bone mean?
Bone burned at a cooler temperature
What can Anthropoligist ID?
Human/ animal Age band Elements present/ absent Minimum number individuals Age, sex, stature, race Identifying features, skeletal or dental anomalies and pathology Reconstruct remains
What is the difference in the age of bones?
Child under 5- three bones
Teenager to young adult- one bone with scar down in
Older adult- one smooth bone
