Identification

likelihood ratio

- > 1 = more likely correct match - < 1 = less likely correct

common x-rays

-40% chest -10% limbs -7-8% spine/breast -5% abdomen/head/neck/pelvis

ident from surgical interventions

-product or brand ident # on the implant -could give (+) ID or just narrow down the pool -identification of ident # may be obscured by remodelling bone -placement is not consistent b/w implants

hard tissue comparisons (5)

-radiographs -surgical interventions -DNA -facial superposition -facial approximation

what does a patgologist use for identification?

-soft tissue -eg fingerprints, scars, birthmarks, tattoos

positive ID

-successfully demonstrates individualization -expert confirmation of unique characteristics -eg dental records, x-ray, etc

types of identification (3)

-tentative -presumptive -positive

how do we narrow down or options?

-biological profile -individualizing features -PMI

using DNA for ident

-body fluids, skin, hair, bone, teeth -considered a unique feature -can determine sex: eg enamel gene -can identify perp, victim, or rule out suspects

using radiographs for ident

-compare AM vs PM -odontology, frontal sinuses, previous trauma, pathological conditions

3 determinations we can make based on identity comparisons

-consistent -not consistent -insuffiecient information

forensic odontology

-dentition is unique (160 unique surfaces) -restorations, dental work, tooth orientation, wear -enough to narrow down the pool at least, not necessarily enough for a (+) ID -combination of all dental traits = 99% confident

using tattoos for ident

-fairly common ident -requires soft tissue and fairly recent remains -not (+) ID, tentative

3D facial approximation

-fill in missing elements of skull, add eyes -place tissue depth markers (based on age, sex, ancestry) -connect markers w/ clay based on markers -add soft tissue features (using artistic license here)

what does a FA use for identification?

-hard tissue -eg DNA, medical records, surgical implants, dental records

craniofacial superposition

-image or 3D rendering of decedent's skull is superimposed over a photo of a missing person -presumptive ID -images must be in the same angle and plane

presumptive ID

-inclusion of additional ID attributes -eg place of death

personal identification

-linking unknown objects/remains back to an individual -informed by context, personal attributes/features/belongings, investigative information, scientific tests/comparisons

tentative ID

-suspected ID based on circumstantial materials -eg driver's license, things friends/family say about why it's them, etc

2D facial approximation

-tissue depth markers -photograph skull -contours drawn onto transparent vellum sheet -skeatch in features

using fingerprints for ident

-unique feature present in recent deaths and well-preserved bodies -can use degloving -ident officer compares prints to database -used as (+) ID but is debated

facial approximation

-used when we have no idea who the person is -becomes a stimulus for recollection -2D or 3D

probability statements

eg "99% chance/match to the individual"

population statistics

used to determine hoe may ppl have a certain feature to determine uniqueness