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Flashcards in Forensic Science Deck (23):
1

What is most useful for Sex Discrimination ?

Skeleton - pelvis and skull

then either prostate or uterus

2

Indicator of ageing from infancy to adulthood

examining the teeth

3

Determination of age - Childhood and adolescence

epiphyses

4

... are very useful in determining foetus and neonate (age)

X-rays

Bone development assessment using ossification centres
24 GW (Gestation Weeks) and term are of most frequent interest

5

.... are most useful for calculation of height

Individual bones of the lower limb

long bones - good

6

In a Mass Fatality Incident, maximum benefit can be gained by helping investigators.....

reconstruct the incident

7

Death is defined as

the irreversible failure of the CVS

8

Can the rate at which the stomach empties be used as a means of measuring the time of death - or the time since the last meal?

No

Too many factors influence the rate at which the stomach empties, e.g. nature/amount of food, solids vs liquids, stress, certain medication

Can offer information on what the deceased last ate depending on the condition of the material remaining

Stress can prevent stomach emptying

9

Stiffening and shortening of muscle fibres leading to rigidity of the musculature and fixation of the joints

Rigor Mortis

reduction of adenosine triphosphate (ATP) within the muscles after death

calcium builds up in the muscles, causing them to tense

therotecically detected in smaller muscles before larger muscles

becomes apparent 5-7 hours after death
usually full established by 8-12 hours
36 hours after death - body in flaccid state

10

A process of “dry” decomposition, with desiccation of the body and a relative lack of bacterial involvement

Mummification

Body essentially “dries out”; the facial features and hands/feet may become rigid
Preservation may be remarkable
Infant bodies particularly prone to mummification

11

Caused by the action of bacterial micro-organisms; process begins at death, but takes a period of time to become detectable

Putrefaction

rem by (petri - bacterial)

12

Induced by the hydrolysis of fatty tissue within the body into a greasy/waxy or brittle material which frequently remains attached to the bony skeleton and may retain the body structure to some extent

Adipocere formation

Tends to occur in damp or wet environments, e.g. bodies recovered from water

13

The condition when all of the soft tissues of the body have completely degraded

Skeletonisation

The process is extremely variable: main variables are exposure to meat-eating animals (post mortem animal predation, e.g. rats) and to dipterous larvae
Radioisotopes have been used to “age” bones, recently including strontium and polonium

14

Represents the pooling of Stagnant blood in dependent regions of the body under the influence of gravity

Post mortem hypoStatis

Usually readily apparent on the external aspect of the body, but may also be observed in the internal organs

Begins as soon as the circulation of blood ceases, but takes time to become visible, usually about 1-2 hours, and fully established by 6-12 hours

not for timing death

15

hypostasis (Red/brown) - may be seen with

methaemoglobin (caused by certain chemicals or drugs)

16

hypostasis - Cherry red colour

indicator of carbon monoxide poisoning

17

Colour of hypostasis can occasionally be

Usually pink/purple in colour

18

Alteration or damage to the body occurring after death which may mimic genuine processes occurring in life

Post mortem Artefacts

• Resuscitation (cardiopulmonary resuscitation - CPR)
• Animal predation (land and sea)
• Traumatic injury

19

cooling - room temp - 1C every hour (sigmoid curve)
circulating blood becomes stagnant - falls under gravity - 1-2 hours
putrefaction - process begins at death, detectable in days
rigor mortis - begins 5-7 hours
skin shrinks
body green 2-3 days
blister formation and tissue swelling - gas formation 1 week

stages of death

20

gold standard comparative methods

fingerprint
dental records
DNA

med information

21

oppportunity for timing of death

first 18 hours

22

measurement of core body temp

first 12 hours

23

timing of death - aL-Alousi and Henssge

accuracy of no better than +/- 2.5 hours

precise timing not possible