Skeletons as Forensic Evidence

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    Cold Case Files are records kept for criminal cases that were never solved, often after several years.  In some cases, however, a murder case may go years before it is even discovered.  In these cases, most portions of the body will have long since either decayed or have been scavenged.  The one portion of the body that takes the longest to decay is the skeleton.  These cases would be, uh, cold, but in a different way . . .  A person who studies skeletons in order to determine information about the person before she/he died is called a Forensic Anthropologist.

    Despite the neglect the dead body endures, there are still quite a number of things that one can learn.  First of all, in the area of the skull, one can determine many things.  In terms of infants, we can determine the age, in weeks, fairly accurately by examining the development of the skull:

Click HERE for the full size image
Original image from http://www.boneclones.com.  Used with permission.

    Notice, apart from the difference in size, how the fontanels (the soft spots that ultimately become the sutures, or fixed joints between the bones in the skull) change over time, gradually becoming smaller.  One must, however, be careful.  Take the following two images, and try to figure out the approximate age of the second image, after examining the first image.

Aged 31 weeks, 32 weeks, and 40 weeks (full term)
Original image from http://www.boneclones.com.  Used with permission.

What age is this skull?
Original image from http://www.boneclones.com.  Used with permission.

    If you had a hard time, perhaps it is due to the fact that the 2nd image was of . . . a chimpanzee skull!  In the same way, bear claws are often confused with human hands.  Can you tell which is which?:

Original images from http://www.boneclones.com.  Used with permission.

    If you are curious, the human hand is on the left.  In terms of forensic anthropologists, they are often called out to identify a bone, only to find that it is not even human, and thus not a crime.  The most common non-human bone found in Connecticut?  . . . .  Ever heard of Spiral Ham?!

    Examine the image below to see how the fontanels, described above, grow and fuse with the other bones to form the sutures.  Although these sutures are as unique as fingerprints, as they cannot be seen antemortem (not without surgery, or a violent accident), they are not useful in terms of identification.

Images purchased from http://www.clipart.com, and adapted by Mr. Lazaroff

    The sutures are, however, useful in terms of determining the approximate age of a skull.  In terms of the sutures, as we grow older, the sutures ultimately completely fill in.  The less filled in, the younger the person.  This does mean that aging has a habit of making us all a bit more hard-headed; this explains a lot about your teachers . . .  We also often tend to lose teeth as we age, and if we really do a bad job flossing, we lose BONE as well, as in the geriatric (elderly) skull below:

Original image from http://www.boneclones.com.  Used with permission.

How do we lose Bone?

NOTE: For more information on Teeth,
see the following links in Forensic Odontology:

Teeth Handout
http://shs.westport.k12.ct.us/forensics/11-forensic_anthropology/teeth_handout.htm
Forensic Odontology
http://shs.westport.k12.ct.us/forensics/11-forensic_anthropology/toothmarks.htm

    In cases where cultures have bound the skull, the sutures have had to move as the bones take on the new shape forced by the binding of the skull.  Note the change in the coronal suture in the skull below:

Peruvian Female, 100 BCE
Original image from http://www.boneclones.com.  Used with permission.

    Age can also be determined, in some cases, by the degree to which the bones show arthritis.  Arthritis can be broken down to the prefix arthr- = joint, and -itis = inflammation.  Arthritis is therefore the swelling of the joints.  One of the effects of arthritis is to change the shape of the bones at the point where the joints are swollen, as you can see in the images below:

Arthritic on the Left, and Normal on the Right
Original image from http://www.boneclones.com.  Used with permission.

Arthritic on the Top, and Normal on the Bottom
Original image from http://www.boneclones.com.  Used with permission.

Close-up view of two Vertebrae:
Arthritic on the Top, and Normal on the Bottom

Original image from http://www.boneclones.com.  Used with permission.

    Another aspect of aging involves the fusion of certain bones with one another, often as a result of a form of arthritis known as osteoarthritis, in which the cartilage in the joints ossifies, which means that it turns into bone.  As there is cartilage between bones (Cartilage that connects bone to bone are called ligaments; cartilage connecting muscle to bone are called tendons.), this process, in essence, creates a larger bone made of the fusion between two bones.  Some common examples in the elderly are shown below:

Top: a vertebra fused with the sacrum
Bottom: the manubrium (top of the sternum)
fused with the clavicle (shown cut here)

Original image from http://www.boneclones.com.  Used with permission.

    At the other end of the scale, there are changes in the body of the vertebrae (the largest portion of the bone) throughout the teenage years, which can be used to determine approximate age at time of death:

Original image from http://www.boneclones.com.  Used with permission.

    X-rays can be used to show comparative age, simply by looking at the end of the long bones, in an area called the epiphysis.  In a child, the area of growth is made of cartilage, and is called the epiphyseal plate.  In the x-ray below, it appears as a clear space running approximately parallel to the end of the bone:

Child's Wrist and Hand, showing the clear lines at the end (epiphysis) of the long bones.
These areas, which are made of cartilage, are the epiphyseal plates, where growth occurs.
Photo from http://www.madsci.org/cgi-bin/cgiwrap/~lynn/image?return=&name=hand_wrist&show_all=1&search=

    In an adult hand (i.e., by the early to mid twenties), however, the growth plate has completely ossified (turned to bone).  At that point, the bones stop growing.  On the x-ray, these epiphyseal lines will appear as white lines in the same location as the plates were in the child's x-ray:

Adult's Wrist and Hand, showing the white lines at the end (epiphysis) of the long bones.
These areas, called the epiphyseal lines, form when the growth plates turn to bone.
Photo from http://www.accessexcellence.org/RC/VL/xrays/1wrist/hndnormu.html

    This growth of bone is also evident in the repair of bone after injuries.  Surgery to the skull is followed by the healing of the bone.  In some rare instances, patients have even survived ancient brain surgery:

Bolivian Female,
Brain Surgery Survivor,
800 AD
Peruvian Male, Bound Skull & Brain Surgery Survivor,
7000 BCE
Original image from http://www.boneclones.com.  Used with permission.

    Unfortunately, not everyone survived the surgery.  Survival, believe it or not, was even more unlikely during the 19th century, when surgeons would go straight from the morgue to the operating theater (and yes, it often was a theater, with seats rising on all sides), without washing their hands!  The greatest proponent, although not the first, of hand washing to reduce infection?  Dr. James Lister!

Inca skull after Trephination.  The lack of bone growth after the surgery indicates that the treatment was likely worse than the disease!
Image purchased from http://www.clipart.com
View of wound in skull after trephination and removal of shattered bone, shown at bottom left. From Charles Bell, The Great Operations of Surgery, London, 1821. Etching by Thomas Landseer, after Bell.
Image purchased from http://www.clipart.com

    Defects in a person's skeleton can sometimes be used to identify an individual, but this often requires a previous x-ray to match the identity, rather like that required of using dental records to make a match.  Some specific defects follow below:

Sternal Defect Scoliosis
Cradleboarding
A prematurely fused sagittal suture, forcing the skull to elongate to allow for the expanding brain during growth.

Original images from http://www.boneclones.com.  Used with permission.

    In some cases the defects themselves are nothing more than the result of surgical techniques.  In the case below, bone grafts from the pelvis were used to repair bones in the forearm (the radius and the ulna):

Original image from http://www.boneclones.com.  Used with permission.

    Another example of a defect following surgery is that of the amputated limb.  The repair of the bone at the distal end (the site of the amputation),. shows that the amputation happened antemortem:

Original image from http://www.boneclones.com.  Used with permission.

Interested in amputations, whether intentional or not?  It turns out that amputated fingers are the most common form of amputation, although most are accidental (whoops!).  For a list of celebrities with amputations, including Darryl Hannah and Mathew Perry, click HERE ( http://www.who2.com/missingdigits.html ).

    In a perimortem injury, however, the bones have no time to heal, so the breaks have clean, sharp edges, as in this case of an American Indian woman who was hit by a truck:

Note the sharp edges of the cuts above.
Note the sharp edges to the skull fractures.

Original images from http://www.boneclones.com.  Used with permission.

    Speaking of healing, broken bones will exhibit a thickened area at the site where the bone healed.  This area is called the external callus.  This can be useful in terms of determining whether a broken bone in a child is an example of an isolated incident, or a pattern of long term abuse.

Note the calluses.
Compression fracture.  Note the callus on the external view (Left)
Original images from http://www.boneclones.com.  Used with permission.

    In addition to recording past fractures, skulls can record a large number of violent acts:

Machete Wounds, African Male
Original image from http://www.boneclones.com.  Used with permission.

Broad Axe Trauma,
Male Spanish Conquistador, 1680 AD
Original image from http://www.boneclones.com.  Used with permission.

Male Roman Gladiator,
with Blunt Force Trauma
NOTE: Above eyes and on either side of the nose.
Original image from http://www.boneclones.com.  Used with permission.

Hammer Wounds
Original image from http://www.boneclones.com.  Used with permission.

    GSWs, or gun shot wounds, leave tell-tale signs on the skull:

Shotgun pellets - the Dick Cheney Effect
(a.k.a. Cheney, Cheney Bang Bang . . .)

Original image from http://www.boneclones.com.  Used with permission.

.410 Caliber
Original image from http://www.boneclones.com.  Used with permission.

Large Caliber GSW
Original image from http://www.boneclones.com.  Used with permission.

Note the fact that the rib started to grow
around the .22 caliber bullet.  That's antemoretem!

Original image from http://www.boneclones.com.  Used with permission.

   In the case of an unidentified skull, it is possible, through slow reconstruction of the musculature underlying the skin, to construct a likeness of the deceased.  This is based on the average thickness of tissues above various bones in the skull (there are 22 bones in all!).  Although this is somewhat accurate, there are a few areas that involve guesswork: eye color, hair color, eyebrow shape, the amount of facial hair in males, the shape of the nose and ears (due to the large amount of cartilage involved, which will no longer be with the skull).  Modern reconstruction involves the use of computers, and has the advantage of allowing the person to manipulate the facial muscles to show the individual in a variety of facial expression!

Reconstruction of the face from the bones of a skull.
SmartDraw image purchased & adapted by Mr. Lazaroff

    It is often possible, but not always, to determine the racial background of a person from a skull.  It is also possible, but once again not always, to determine the gender of a person from a skull.  See if you can see any patterns from the examples below:

African Male African Female
African Male
Original images from http://www.boneclones.com.  Used with permission.
 
Asian Male Asian Female
Asian Adolescent Female
Original images from http://www.boneclones.com.  Used with permission.
 
European Male European Female
Original images from http://www.boneclones.com.  Used with permission.

Hispanic Female, with Trisomy 21 (Down's Syndrome)
Original image from http://www.boneclones.com.  Used with permission.

Australian Aborigine Male
Original image from http://www.boneclones.com.
Used with permission.

    In some cases, identification of gender is impossible (Note: that is not specific to any one racial group, but rather a fact common to all races.):

Native American (from the Southwest)
Gender Unknown
Original images from http://www.boneclones.com.
Used with permission.

    Some skulls can show characteristics of the opposite sex, making identification difficult:

Masculinized Female
Original image from http://www.boneclones.com.
Used with permission.

    Last, but not least, during early childhood development, one of the most accurate indicators of age involves the teeth that have erupted.  Given that, note the effect of malnutrition on the child from 6000 BCE, and compare that to the 2 year-old below, and you can see the difference in the teeth.  The 30 week-old fetus is included for comparison purposes.  Severe malnourishment, when at the hands of a parent, is grounds for charges of child abuse.

Modern 5 Year-old (LEFT)
Malnourished 5 Year-old,
circa 6000 BCE (RIGHT)
2 Years Old 30 Week-Old
Fetus
NOTE: The two images to the right are not exactly to scale, but only approximately.
Original imageS from http://www.boneclones.com.  Used with permission.

QUESTIONS:

1. What are two ways, other than size, to determine whether a skeleton is from a teenager or an adult?

2. How can you tell whether an injury occurred perimortem (around the time of death) or antemortem (well before the time of death)?

3. What are 5 things that you can determine about an individual adult from that person's intact skull?