If These Bones Could Speak

Greetings my dear reader !
How are your investigations so far? Have you been giving any thoughts to Question 4? :) 

"Question 4

Other than examining the dental aspects provided as evidence, what other ways can the victims be identified?"

If we were to hand you a bag of bones, will you be able to tell if they're from a human or non-human? And whether the bones belong to the victim or somebody else? 

The answer is YES, you can. However, it would be better for you to be at the excavation site or crime scene to be able to get a clearer picture of the identification of a victim. Let us determine other methods to identify a victim, other than relying on dental aspects as evidence :) So for this section, skulls and teeth or anything related to dental aspects will not be discussed. You may refer to the dental aspects in Chapter 1 : Fancy Yourself As A Detective if you wish.

Let's watch a video by us first ! Introducing our first MTI Goodness part 1 !

I guarantee you'll love it ;)

Firstly, we are going to introduce Forensic Anthropology to you. The information provided are in point forms for easier understanding ! :)

What is it? 

-          Combines theories and methods of anthropology, osteology and archaeology

-          A scientific study of human remains, collect and analyse human remains, with the purpose of identification of victims, estimation of time since death, establishment of injuries, cause of death

-          FA can determine age, sex, race, stature of deceased and many other factors about one’s lifestyle and culture

-          Normally victims are examined in the late stages of decomposition (completely skeletonised or unrecognisable due to injuries, etc) 

-          When suspected human remains are first found, forensic anthropologists will be called in

-          Forensic anthropologists will help more if they are present at the excavation site. From there, they can tell if bones are humans, teeth or other pieces can be collected to determine factors such as race

-          Forensic anthropologists are also involved in non-criminal matters (natural disasters)

Next, we move on to steps ! What do they do in general? 

Steps

-         “Doing the big four” , identifying age, sex, race and stature

-          After data collection and examination of skeleton, they transmit data to national forensic skeletal data bank ( For two reasons : to provide overview of population that is constantly changing, to allow scientists to compare the results of their examinations and hence determine probabilities of accuracy of their results)

How to tell if the set of remains are those of a specific person?

-          Process of elimination

-          Try not to know anything about the case because it can bias you, examine the remains objectively

-          Looks at skull first, find out age and sex

-          Compares skeletal DNA to DNA from mother

-          Injuries can be matched to X-rays or diseases traced to scars on certain bones

-          Teeth can indicate that the person took antibiotics at a particular time

THE BIG FOUR ! The methods mentioned below will help you to identify the victim better !

Age

As we age, ossification occurs around 800 points in our body. What is ossification? It is when separate pieces of bone fuse together, sutures are formed, appearing in zigzag seams. You have to know that fusion of particular bones occurs at specific points in life. So from there, you can find out the victim's age.

-     Around age 6, two bone plates form at either end of radius bone in arm

-     The lower bone plate fuses with radius, at 17 years old in males, 20 years old in females. The upper bone plate then follows.

-     Fusing of epiphysis (rounded end) of a bone to the diaphysis (bone shaft) are indicators

-     Epiphyses are soft in growth period, hardens into bone and fuse with main shaft in adults

Picture adapted from : http://fleshandbones1.blogspot.com/2010_04_01_archive.html

-     Head of femur fuses between 18 and 20 yrs old, part of the hip undergoes same process and around 24 yrs old. After this point, this fusing is useless in age determination

-     Certain sections of cartilage around body turn into bone over time at particular age.

-     At birth, the wrists are composed of cartilage, forming bone later. If victim is under 13 yrs old, a wrist x-ray is taken

-     Study pubic symphysis, the midline joint between left and right pubic bones. The two pubic bones are joined by cartilage, over time it will smoothen

Another way is osteon counting by microscopy. What are osteons? Osteons are minute channels where they house the nerves and blood vessels. The more osteons, the older the victim. 

Picture adapted from : http://www.bownet.org/tmack/A&P_Skeletal%20System%20Test%20Review%20_overview.htm

Age of remains

-          Carbon dating (radioisotope carbon-14 is taken by an organism) is performed

-          Half life of carbon-14 is known as being 5700 years, so you just need to find the amount of isotope remaining in the sample or victim

Click on the video to find out how to carbon-14 dating works! :) 

Sex

The most obvious clue is the pelvic bone.

-          Women have wider pubic bone to allow room for a baby’s head to pass through during childbirth. Their sub-pubic angle is of more than 90 degrees

-          Men’s sub-pubic angle is less than 90 degrees

-          Use of pelvic bone is accurate (95%), but not useful when the victim is a pre-pubescent child

LEFT : MALE, RIGHT : FEMALE. Picture adapted from : http://anthropology.si.edu/writteninbone/male_female.html

Here are the differences between a male and female pelvic bone.

Male	Female
narrower, heart-shaped pelvic inlet	open, circular pelvic inlet
narrower sciatic notch	broader sciatic notch
narrower angle where the two pubic bones meet in front	wider angle where the two pubic bones meet in front
	more outwardly flared hip bones

Picture adapted from : http://home.comcast.net/~wnor/pelvis.htm

Ethnicity/ Race

-          Caucasian has a narrower face and high bridged nasal bone, upper incisors are flat lingual surface, chin more prominent, cheekbones fairly high and flat

-          Negroid has a broader nose bridge with wider nasal openings and subnasal grooves, skull has outward slopping jaws, flat lingual surface of upper incisors

-          Mongoloid has a broader face, squarer, forward sloping, wing like cheekbones and lower nose bridge, upper incisors are shovel shaped, skull is flatter

Negroid, Mongloid, Caucasian (from left to right), 
Picture adapted from : http://news.brown.edu/pressreleases/2009/01/race

Stature, Weight, Individual Differences

-          Pubic bone, pelvic inlet widens after childbirth for women

-          If skeleton is a whole, use direct measurement to find out height, with few inches added to account for flesh. Otherwise, use formula based around length of a long bone such as humerus or femur. Human height is two and two thirds of the length of femur.

-          Another method is the measurement from fingertip to fingertip of outstretched arms, the length is about body height

-          Weight is difficult to find out; layers of fat leave no markings on bones. So, look for clothes worn. Well developed muscles will leave clear markers on bones. From there, you can find out about one’s lifestyle

-          Use medical records and compare with what you have found. Diseases, previous injuries and birth defects leave marks on bones.

Furthermore, there is also a method called facial reconstruction. You can create a clay model using the victim's skull or in a more advanced technique, a computerised 3D facial mapping.

Clay Model

Computerised 3D Facial Mapping,
Picture adapted from : http://www.mpi-inf.mpg.de/departments/d4/areas/physicsbasedmodeling/

Stay tune for the next post on DNA profiling ! Another extremely important method to determine the identification of the victim !

References : http://forensicsciencecentral.co.uk/anthropology.shtml