Biological Profiling (Forensic Anth)

Big 4 of Biological Profiling

Ancestry, Sex, Age, and Stature

Order of Estimation

The order of estimation outlines the sequence of which estimation examiners should do first

1. Ancestry

2. Sex

3. Age

4. Stature

Order of Accuracy

1. Sex

2. Age of Subadult

3. Stature

4. Age of adults

5. Ancestry

Population vs. Sample

Population: the global or total set of something

Sample: A subset of the population

Anthroposcopic Method

• Gross observation of patterned traits

• Present or absent

• Looking for varying degrees of present patterns

• Morphoscopic (the visual assessment of skeletal shape, structure and features)

Osteometric

• Metric (measured)

• Index

• Statistics

Ancestry in Forensics

• Categories - African, Asian, and European

• Based of US societal constructs (not evidence)

• Problematic

• Some skeletal variation is geographically patterned

Morphoscopic Estimation of Ancestry (Key Features)

• Anterior Nasal Spine (ANS)

• Inferior Nasal Aperature (INA)

• Interorbital Breadth (IOB)

• Nasal Aperture Width (NAW)

• Orbit Outline Shape (ORB)

• Post Bregma Depression (PBD)

• Mental Eminence Shape (ME)

• Femur

Shovel Shaped Incisors

Asian trait

Anterior Nasal Spine

Slight = African

Intermediate = Asian

Marked = European

Inferior Nasal Aperture

Sloped or Partial Slope = African

Straight - Sill = Asian - European

Interorbital Breadth & Nasal Aperture Width

Broad = African

Intermediate = Asian

Narrow = European

Orbit Outline Shape

Rectangular = African

Rounded = Asian

Oval = European

Post Bregma Depression

Absent = Asian or European

Present = African

Mental Eminence Shape

Rounded = African

Broad or Intermediate = Asian

Squared = European

Femur

• Anterior curation of the diaphysis

• Torasion of the neck

• Intercondyler shelf angle

Estimation of Sex

• More pronounced in adults

• Best indicator: Pelvis

  • 90-95% Accuracy

  • Cranium and Other Postcrania ~80-90%

• 3 categories: Female, Male, Intermediate

Pelvis Sex Estimation: Male

• Male

  • Size: large and rugged

  • Ilium: high and vertical

  • Pelvic Inlet: heart shaped

  • Subpubic Angle: V-shaped

  • Pubic Shape: narrow and rectangular

  • Greater Sciactic Notch: narrow

  • Pre auricular sulcus: rare

  • Shape of Sacrum: long and narrow

  • Obturador foramen: large and oval

Pelvis Sex Estimation: Female

Female

• Size: Small and gracile

• Ilium: low and flat

• Pelvic Inlet: circular

• Subpubic Angle: U-shaped

• Pubic Shape: broad and square

• Greater Sciactic Notch: wide

• Preauricular Sulcus: well developed

• Shape of Sacrum: Short and broad

• Obturador Foramen: small and rectangular

Phenice Method

Phenice Method: ranking pubic features from 1 to 5 ~90-95% accuracy

• Greater Sciatic Notch: broader in females

• Ventral Arc: females have a ridge on ventromedial aspect of pubis

• Subpubic Concavity: "bowing" of inferior pubic border in females

• Medial Aspect of the Ischiopubic Ramus: females have a sharp border

Pelvis Sex Estimation: Metric Ischium-Pubis Index

Pubis length x 100/Ischium length

• below 90 = Male

• 90-95 = Intermediate

• 95+ = Female

Pelvis Sex Estimation: Metric Sacral Index

Anterior Breadth x 100/Anterior Height

• Above 117 = Female

• Below 117= male

• (Lots of overlap)

Cranium Sex Estimation

• Nuchal crest - robust/male, gracile/female

• Mastoid process - Large/male, small/female

• Parietal boss - marked/female, reduced/male

• Supraorbital margin - sharp/female, rounded/ male

• Supraorbital tori/Glabella - defined/male, reduced/female

• Calvaria shape (frontal) - rounded/female, sloped/male

• Mental eminence - defined/male, rounded/female

• Gonial angle - oblique/female, right/male

• Gonial flare - flared/male, unflared/female

Cranium Sex Estimation: Scoring System

1) Female

2) Probable female

3) Ambiguous sex

4) Probable male

5) Male

FORDISC

Computer Program used to estimate sex, ancestry, and stature

• compares two populations for affinity

Age at Death: Subadult

• 2nd most accurate demographic estimation

• Developmental processes

  • Dental development

  • tooth eruption

  • Bone growth

  • Epiphyseal fusion

• Nutrition and health can greatly effect age and stature estimations

Age Estimation: Dental Formation

• Eruption of deciduous and permanent teeth

• Most accurate age estimation technique from birth to 10-12 years

Dental Eruption Schedule - Deciduous

• First tooth erupts at 6-9 months

  • Lower central incisors

  • Formation of deciduous begin by the end of 6 months

• Last eruption by 2-3 years (complete)

  • Second molars

Dental Eruption Schedule - Permanent

• Molar 1 erupts ~6 years

• Incisor 1-2 erupts ~6-9years

• Canines, Premolars, and Molar 2 ~10 years

• M3 ~18-25 years but is erratic

  • Can be used for ID

Bone Development - Subadult

• Epiphyseal Fusion

  • Ends ~21-22 years (range of 16-32+)

  • Activity greatest between 15-23 years

• Diaphyseal Length

  • can be used until the epiphyses fuse ~10 years

  • Best for fetal age estimation

Age Estimation - Adults

• Pubic symphysis

• Auricular surface

• Sternal ends of ribs

• Cranial suture closure

• Dental wear

Age Estimation: Pubic Symphysis

Phases:

• Phase 1 (15-23): Ridged surface, no beveling, no symphysis rim, no lipping

• Phase 2 (19-35): Nodules and beveling, ventral beveling begins

• Phase 3 (22-43): Ventral rampart complete, no rim, no lipping

• Phase 4 (23-59): Smooth face, oval outline almost complete, no rim, no lipping

• Phase 5 (28-78): marked rim and lipping,

• Phase 6 (36-87): erratic ossification, irregular lipping

Best method for adult age estimation

Changes in billowing, boarder, face shape, etc.

Age Estimation: Auricular Surface

Changes in billowing, striae, porosity, surface changes, etc.

~20-46 yrs: billowing, fine striae, and fine granularity

~20-75 yrs: Course granularity, porosity present

~24-89 yrs: irregular surfaces, porosity, dense surface

Age Estimation: Sternal Ends of Ribs

Billowy to marked, flat to cupped

~20-30 yrs: Shallow pit, billows

~27-49 yrs: Rim around pit, rim is flared, no projections

~47-99 yrs: Pit is deep, bony projections around rim, irregular rim, body nodules

Age Estimation: Cranial Suture Closure

0 - open

1 - partially open

2 - Partially obliterated

3 - obliterated

Age Estimation: Dental Wear

• Exposure of dentine

• Most useful for prehistoric or paleo contexts

• Not very accurate in modern context (~60-75% for adults ± 10yrs, but 90% for ± 50yrs)

Stature Estimation

• Whole body measurements

• Whole skeletal measurements

• Quick estimations

  • Body is roughly 5x length of the humerus

• Osteometric: regression formulae using long bone lengths

  • Tibia, Femur, Fibula, Humerus, Ulna, etc.

Stature Estimation: Whole Skeletal

• Skeletal height = sum of bones 1-6

  • 2 = sum of all vertebrae C2-L5

  • 3 = S1 only

  • 6 = Talus and calcaneus

• Add and Subtract standard 2 x Standard Error of the estimate (SE)

Stature Estimation Formulae (Important Info.)

• Femur is best for single

• Lower limb is better than upper limb

• Multiple elements best