Forensic context lectures 5&6 Flashcards
What is medico- legal remains
those of which cause and manner of death are determined and death certificate is generated, remains less 50 years old
Cause of death
disease of injury that initiates a sequence of events that result in death
What is manner of death?
the manner in which the cause of death comes into being
(homicide, suicide, accident, natural)
What differences does bipedalism make in a human skeleton?
pelvis is shorter and wider
vertebrae thicker and flatter, double curve
foramen magnum is anterior on the skull
Circular osteons
randomly places
various sizes
Histological human
osteons and other structures
can be banded
plexiform, brick-like lay
Histological non-human
What are 5 factors used to help assess if the remains are contemporary
- state of preservation
- body mod (intentional and unintentional)
- color
- personal belongings/ material
- conditions of interment
Types of non medico-legal remains
- anatomical (for teaching)
- trophy, ancestor skulls
- looted historic and prehistoric grave (still a crime)
How can you tell this is a skull fragment
two layers of compact bone separated by spongy diplo
How do you identify a clandestine grave
disturbed vegetation
soil compaction
secondary depression
disturbed soil
How can you tell the soil has been disturbed
crushed plants
grave pit depression
Loss of color within 15 minutes of death
pallor mortis
What is the postmortem interval?
This is the amount of time that has passed since the decedent’s death and
their discovery by law enforcement.
Tache noire de la sclerotique
dark band forms on the sclera of the eyes due to drying
When blood begins to settle
livor mortis
the muscle begins to stiffen
rigor mortis
Decomposition caused by bacteria
putrefaction
As the cells die, they release their enzymes that begin the process of decomposition as the body begins to digest itself
autolysis
__________ is the most important variable that affects the rate at which the body deteriorates. Higher ___________ result in quicker decomposition because autolysis, putrefaction, and insect activity are all accelerated at higher ______________. For this reason, researchers no longer think that time is the dominant variable affecting decomposition rates.
temperature
No discoloration except for lividity and incipient marbling of the veins; no insect activity except for possible blowfly eggs near orifices
fresh
skin slippage; hair nail loss; pink discoloration of skin; darker discoloration of face and fingers; flies and maggots present near eyes, nose, and mouth. marbling of veins is darker w/ decomposition fluid oozing from orifices
Early decomp
a) Pre-bloating
abdomen bloated and discolored green; beetles present
Early decomp
b) bloating
body ruptures; discolored brown to black
early decomp
c) post - bloating
abdomen collapsed with skin sagging due to extensive maggot activity; remains are still moist; beetles are still active on corpse
advanced decomposition
skeleton largely exposed with some remaining flesh and ligaments
beetles dwindling; bones are greasy and yellow due to remaining fat
eventually drying white
skeletonization
bones are sun bleached; cracks forming along long bones; cortical bone peeling away. later stages the long bone ends are destroyed
skeletal decomposition
the body temperature drops toward the ambient air temperature
algor mortis
What is the primary role of a forensic anthropologist in a death investigation?
To estimate the postmortem interval in cases of skeletonization.
what is considered the most significant in affecting the rate of decomposition
temp of the environment
How does the presence of insects influence the decomposition process?
Insects accelerate decomposition by consuming soft tissues and generating heat.
What role do forensic entomologists play in death investigations?
They use insect biology to aid in estimating the postmortem interval.
How does the concept of accumulated-degree-days (ADD) relate to decomposition?
ADD is used to estimate the time it takes for a body to skeletonize based on temperature.
which is simply the sum of the average daily temperatures that a corpse experiences A general rule, the time it takes to reduce a body to a skeleton = 1285/average daily temperature.
This means that if the average daily temperature is 40oC (104oF) the body will skeletonize in approximately 32 days (1285/40=32).
accumulated-degree-days (ADD)
the study of what happens to the body and how the environment impacts on these processes between the death and discovery of human remains.
Forensic taphonomy
the study of insects and other arthropods found at crime scenes to help solve cases.
forensic entomology
tend to be more open and flared in females, reflecting the wider pelvic girdle. The female pelvis is wide and shallow, while the male pelvis is narrow and tall.
blades of the ilia
tends to be more oval in females and more heart-shaped in males.
pelvic outlet
is more triangular in females and more oval in males
obturator foramen
“sex-based two forms”; that is the tendency for males and females of a species to vary in size, with males being larger than females in primates and most mammals
Sexual Dimorphism
