Forensic Science Flashcards
What is most useful for Sex Discrimination ?
Skeleton - pelvis and skull
then either prostate or uterus
Indicator of ageing from infancy to adulthood
examining the teeth
Determination of age - Childhood and adolescence
epiphyses
… 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
…. are most useful for calculation of height
Individual bones of the lower limb
long bones - good
In a Mass Fatality Incident, maximum benefit can be gained by helping investigators…..
reconstruct the incident
Death is defined as
the irreversible failure of the CVS
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
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
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
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)
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
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
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
hypostasis (Red/brown) - may be seen with
methaemoglobin (caused by certain chemicals or drugs)
