Forensic Anthropology -- Case Report

Inventory Condition of Bones Profile Sex Race Age Stature Weight Manner/Cause of Death

The Case Report

Introduction

When a human body is discovered, the primary objectives in an investigation are to identify the body and to establish the cause and manner of death. For this lab project, I needed to estimate the sex, race, age, stature, weight, and any pathology of a newly acquired partial skeleton. This skeleton had been sitting in storage for several decades in a basement and very recently was stored in a drawer on a shelf in the lab office. Below is an inventory of the bones and their overall condition:

Inventory

Skull	The skull was intact but with a hole in the left parietal/temporal area
Dentition	1. Maxilla contains 5 partial teeth: I1, C and P on right; I1, I2 on left. 2. Mandible contains all 4 I, both C, P1, P2 on right; P1 M3. a. There is noted calcification of bone where M1 and M2 would be on left. b. Decay is noted on P2, right side.
Pectoral Girdle:
Scapula	Right and Left scapula were minimally present; probably from wear and tear on the skeleton including rodent gnawing, but not due to trauma occurring before or during death
Clavicle	Right and Left clavicles were partially present
Arm:
Humerus	Right and Left intact, still wired to Radius, Ulna, and Hand
Radius	Right and Left intact, still wired to Humerus, Ulna, and Hand
Ulna	Right and Left intact, still wired to Humerus, Radius, and Hand
Hand:
Carpals	Complete Left, wired to Radius and Ulna; Right see description
Meta-carpals	Complete for Right and Left, wired to Carpals
Phalanges	Complete for Right and Left, wired to Metacarpals
Vertebral Column:
Cervical (7)	Complete. Bent into unnatural position because of bar through vertebral foramen
Thoracic (12)	Complete
Lumbar (5)	Complete
Sacrum	Complete
Coccyx	Complete
Ribs	Twelve per side
Pelvis:
Ilium, ischium and pubis	Most of the ilium was missing, the pubis was mostly intact as was the ischium.

Note that the long bones of the lower body, along with the bones of the feet were not present for analysis.   Top

Condition of Bones

The overall condition of “Earl’s” skeleton was poor due to decades in storage where rodents, most likely mice, found ample opportunity for gnawing to keep their teeth a manageable size. Tooth marks were noted on ribs and pelvis. A hole in the left parietal/temporal region of the skull measures 2.5 (h) x 2.3 (w) and may have been caused by infection in life or by bugs and/or rodents post-mortem. When the skull was placed in the Frankford Plane, prognathism was noted.

Both hands were almost complete and wired to the carpals, ulna, radius and humerus. The right hand, however, presented damage either due to rot or rodents. Damage was noted in the carpals as well as the metacarpal bases. In the right wrist, both the hamate and capitate are partially missing, and the lunate is missing

The rib cage was mostly complete with the exception of the clavicles medially, and the last 3 ribs on either side medially. Bone rot and cartilage rot (or rodent damage) was noted.

The left blade of the scapula is mostly missing although the axillary border exists, along with the acromion and spine. Both scapulae were noted to be in extremely poor condition with portions non-existent.

The right iliac blade is 80% missing. Rodent gnaw marks were noted. Posterior portions of the blade that remain are bone but cortical bone eroded on medial side and is mainly cancellous bone. The left iliac blade is 95% missing and what remains is similar to the right blade in composition. The right acetabulum is nearly intact except for a small irregularly shaped hole, again possibly rodent as tooth marks have been noted previously.

The pubic symphysis is missing, but the ischium is complete. The sub-pubic angle was noted to be sharp (male). The greater sciatic notch is sharply angled but the pubic bodies are missing, as is the left superior pubic ramus; the right is partially intact. There is not enough bone to make a pelvic inlet sex determination.

As noted above in the chart, some teeth were still in their sockets, however in poor condition. Most of the crowns were either missing or greatly worn. Cusp pattern on the remaining molar was not determined.   Top

Profile

Positive identifications can be obtained in a number of ways. When the soft tissue is still intact, the usual means of identification is through visual identification or fingerprinting. Once the soft tissue has decomposed, the means of identification becomes more complex. Dental comparison is the easiest means of identification, if pre-death dental records are available for comparison.

A forensic anthropologist is used to determine a profile of the deceased to narrow the search of missing people. The anthropologist will provide the police, or other law personnel, with a profile of the sex, race, age, stature, weight of the individual, along with any other useful information, such as any unusual pathology. This information is then compared with missing persons’ records to find a possible match (Hunter etal).

A problem possibly encountered by others is that in order to determine race, the sex needs to be known. But to determine sex, the race needs to be known. Only after taking many measurements and plugging them into the myriad of formulas can one finally make a reasonable determination.   Top

Sex

Using direct observation of the skeleton’s morphology, I noted that the skull exhibited both male and female traits. The greater sciatic notch of the pelvis, on observation, was decidedly male. It was determined to be male based on measurements plugged into the Gender Recognition with the Use of Discriminant Function and Skull Measurements formula on page 55 of the textbook (Steele etal).

	Male	Female	“Earl”
General size	Large	Small	Male
Architecture	Rugged	Smooth	Male
Supraorbital margin	Rounded	Sharp	Female
Mastoid process	Large	Small	Male
Occipital bone	Muscle lines and protuberance marked	Muscle lines not marked	Male
Glabella	Boney	Flat	Female
Gonial Angle	Squared	Wide angle	Female
Palate	Larger, broader, tends to be U-shaped	Small, tends to be a parabola	Male
Occipital condyles	Large	Small	Female

The metric measurements are based on skull landmarks that are illustrated in the following drawings from Bass (1987:63-64). The skull landmarks referred to are: glabella (g), opisthocranion (op), euryon (eu), nasion (n), nasospinale (ns), alare (al), gnathion (gn), and zygion (zy).

Sliding calipers and spreading calipers are used to take the measurements. The purpose of these particular measurements is to separate (or section) male from female... or black from white from Indian.

            Gender Recognition for American Black:
            3.895(g-op) + 3.632(eu-eu) + 1.0(ba-b) – 2.053(ba-n) + 12.947(zy-zy) + 1.368(ba-ids) + 8.158(ids-n) + 19.947(po-ms) = [4079.12] 86.6%

            Plugging in the measurements taken:
            3.895(19.5) + 3.632(13) + 1.0(14.3) – 2.053(10.4) +12.947(13.5) +1.368(10.4) + 8.158(8.05) + 19.947(2.9) = x 10*

The sectioning point is 4079.12; anything above this number indicates the sex is male. *The sum needs to be multiplied by 10 to accommodate for differences in measuring scales (i.e.: cm to mm). “Earl” is above this sectioning point.   Top

Race

Using the Discriminate Function Analysis (DFA) on page 59 in the textbook (Steele etal), “Earl” appears to be a Black American male. The following computations were used to determine the race recognition from cranial measurements:

            DFA to separate White and Native American from Black:
            1.6(g-op) -1.9 (eu-eu) - 1.79(ba-b) - 4.41(ba-n) - 0.1(zy-zy) + 3.06(ba-ids) + 2.59(ids-n) + 10.56(al-al) = [89.27]

            Plugging in the measurements taken:
            1.6(19.5) -1.9 (13) - 1.79(14.3) - 4.41(10.4) - 0.1(13.5) + 3.06(10.4) + 2.59(8.05) + 10.56(3.05) = 23.86x10*= 238.60

The values within parentheses refer to the cranial measurements found on pp.66-68 (Steele etal). The sectioning point is in the brackets and a score below this point would indicate that the skeleton is White. A score above this point means that the skeleton is Black. *The sum needs to be multiplied by 10 to accommodate differences in measuring scales (i.e.: cm to mm). Since “Earl” scored 238.60 on the DFA, and is well above the sectioning point of 89.27, it was determined that “Earl” was a Black American male.

DFA was also used to determine if “Earl” could have been American Indian. The sectioning point is 22.28. “Earl’s” score was 10. Additionally, checking this number against the chart shown on page 60 (Steele etal) indicates that “Earl” is neither White nor Native American.

            DFA to separate Black and White from Native American:
            -0.25(g-op) -1.56 (eu-eu) + 0.73(ba-b) – 0.29(ba-n) + 1.75(zy-zy) - 0.1(ba-ids) – 0.16(ids-n) – 0.84(al-al) = [22.28]

            Plugging in the measurements taken:
            -0.25(19.5) – 1.56(13) + 0.73(14.3) – 0.29(10.4) +1.75(13.5) – 0.1(10.4) – 0.16(8.05) – 0.84(3.05) = 1x10* = 10   Top

Age

Based on the Ectocranial Suture Closure table (Steele etal), “Earl” was determined to be between 26 and 35 years old at the time of death. The Coronal suture was closed laterally but not bregma (closure range beginning to end: 24-41 years old). The Lambdoid suture (closure range beginning to end: 26-42 years old) was fused at its meeting point with the Sagittal suture. The Sagittal suture (closure range beginning to end: 23-35 years old) was partially closed where it meets the Lambdoid. Therefore, using the highest age of the low end and the lowest age of the high end of the ranges above, it was determined that this skull belongs to an individual who was at least 26 years old and not older than 35 years. However, it should be noted that ectocranial “suture closure is not a reliable indicator of age since skulls exhibit very large variability in rate of closure (Steele etal).”   Top

Stature

“Earl’s” stature was determined using the Regression Formula for Estimating Stature (with standard errors) from Maximum Long Bone Length of the Humerus on pg. 169 (Steele etal), using the average of both right and left humeri, both right and left ulnae and both right and left radii. The average of the standard error was 4.38.
            3.26 x (humerus) + 62.10 = stature +/-4.43cm
            3.42 x (radius) + 81.56 = stature +/-4.30
            3.26 x (ulna) + 78.29 = stature +/-4.42

Humerus
Right	Left	Average	Standard Error
33.3	33.4	33.35	+/- 4.43
Radius
Right	Left	Average	Standard Error
25.9	25.9	25.9	+/- 4.30
Ulna
Right	Left	Average	Standard Error
28.5	28.4	28.45	+/- 4.42

Using the average for each bone in the formula and the average of the standard error (4.38):
            3.26(33.35) + 62.10 = 170.82 (humerus)
            3.42(25.90) + 81.56 = 170.14 (radius)
            3.26(28.45) + 78.29 = 171.04 (ulna)

The average of the bone lengths is 170.67 +/- 4.38.
            170.67 + 4.38 = 175.05 cm and 170.67 – 4.38 = 166.29 cm.

A conversion from cm to feet and inches (divide by 2.54) is as follows:
            175.05/2.54 = 68.92” which is 5’9”
            166.29/2.54 = 65.47” which is 5’6”

Therefore, “Earl” would have been between 5’6” and 5’9” in life.   Top

Weight

Using a formula given to us last year in Forensic Anthropology class for calculating a skeleton’s living weight without weighing the bones, it was determined that “Earl” weighed between 145 lbs and 160 lbs.
            4.4 x (stature in inches) – 143 = Wt (lbs)
            4.4 x (65.47) – 143 = 145.06 lbs
            4.4 x (68.92) – 143 = 160.25 lbs   Top

Manner and Cause of Death

The bones available for examination offered no explanation for manner or cause of death. No obvious injuries were noted, except for the postmortem hole in the skull noted above.   Top

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