Forensics Individualization ind

individualization ID methods

* facial reproduction/reconstruction
* assessing handedness
* estimating body weight

Individualization

can increase the likelihood of a match between human remains and a missing persons file

Individualization issues

* most of these techniques are not widely used
* debar as to their reliability

facial reproduction

* clay sculpting
* artist drawings
* computer graphics

facial reproduction goal

recreate the appearance of the persons face in life

facial reproduction history

* beginning in late 1800s
* only very recently used for forensic casework
* use landmarks for measuring
* thickness standards are estimate from cadavers

facial reproduction- errors

* skin thickness differences between dead and living
* inward deformation of tissue at the point of insertion
* difficulty with finding the exact location of measurements
* sex, weicht, and ancestral differences

facial reproduction techniques

3D surface and CT scanning are used to get facial thickness

Assessing handedness

estimate by observing which side of the skeleton has the largest and most modified bones

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Handedness cannot be determined with accuracy from the skeleton

T.D. Stewart

(1979) he argued that handedness can be estimated

Assessing handedness- issues

* most more recent studies do not support this
* differing definitions of handedness
* greater % of right than left handed

Estimating body mass

* new research
* combines knowledge of biomechanics and pathology

pathology

Emaciation and obesity, could also be from extreme body building

Emaciation

hypertrophic pathologies, low bone material density

Obesity

DISH in spine, osteoarthritis, and other degenerative diseases; trauma to the medial side of the knee

Biomechanics

* cross sectional area of the femur
* bone mineral density
* both are highly correlated to weight

Estimating body weight steps

* estimating stature and sex
* use height- weight charts to correlate the two
* observe skeletal robusticity and muscle markings

estimating body weight issues

* wide variations exist between factors and did not stand up to validation
* small sample sizes
* low accuracy rates
* estimates are rough estimates

cremation

cremation of the dead dates back to antiquity

cremation in the US (contemporary)

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* Body placed in receptacle like wooden casket or heavy cardboard container
* Temperatures of 1500-1600F created by air jets
* After cremains cook, a magnet is used to remove metal objects
* Cremains are mechanically pulverized
* Cremains transferred to urn or other container

Cremation: difficulties

due to changes of the bone

* heat
* mechanical reduction

cremation- goals of analysis

* confirm remains are human
* confirm remains represent 1 individual
* establish remains most likely belong to a particular individual

cremation- steps of investigation

* total weight
* microscopic analysis of osseous materials
* microscopic analysis of nonosseous materials
* NO DNA- temps are too hot

osseous materials

bones and teeth

non osseous materials

cremation artifacts

osseous characteristics

* degree of color change
* amount of fragment versus ash
* lead and calcium content in remaining fragments

no osseous characteristics

* coffin hardware
* medical and dental artifacts