Part II : Murder Most Brutal !

After a week of hiatus, we are back on the investigation with some new information and evidences ! :D Our group has come together and brainstormed to solve this mystery case, trying our very best to think like professional detectives :p It was indeed very challenging to push ourselves to pick up details, connecting the dots, and slowly figuring out and resolving the case together as a team :)

The following would be our findings and hopefully it is informative and helpful :) 

Question 4 

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

There's a necessity to identify a deceased due to many incidents and at times, bones are the only accessible source for examination.  Forensic odontologists have done a great job in aiding the identification process.  A successful alternative is to use DNA technology for identification process.  Typically, this process involves the usage of short tandem repeat (STR) markers and fluorescent technologies, which are widely used in the field of forensics.  However, in certain aged and burned bones, DNA is highly degraded and the process for DNA extraction may become more complicated and handful.  The major challenges during the process is to maximize DNA yield, minimize the possibility of outside contaminants and obtain high quality DNA samples.

The other simpler way to aid the identification process is to create a biological profile for the victims.  There are few parts of the bones that can be examined to determine their age, sex, height and to a further extend, their occupation or maybe are they malnutrition or not.  The following aspects that should be examined :

• Epiphyseal union - As a person ages, the areas of the femur gradually fuses together.  This can help to estimate young ages if the teeth are missing.

• Pelvic girdle - Female's is always wider than male's.  This is the dramatic identifiers of sex of the victim.

• Wrist - Bony ridges form where muscles were attached and pulled over years.  A forensic anthropologist may find a bony ridge on wrist and decide the victim may have been someone who used their hands for living, such as a chef or seamstress.  

• Sternum - Examine the region where ribs join to sternum and compare it with a database of standard markers.  This is a good way to identify victim's age.

• Skull - Examine the sagittal suture. If it is completely fused, the victim is likely to be of someone older than 35.  Then examine the coronal suture which fully fuses by age of 40

•  Decomposition - By looking at the stage of decomposition, we can estimate the time of death of the victim. The stages of decomposition are :

1) fresh stage (three days after death)

2) putrefaction stage (between days 4 and 10)

3) black putrefaction stage

4) butyric fermentation stage

5) dry stage

have a look at the article from the link below to know more about this part of forensic science! :)

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

Question 5

Part 1

List the evidences that have been presented to both the doctors.

• An adult skull with a large jaw bearing five teeth
• A child's jaw with some teeth still in eruption
• A piece of jaw bearing three back teeth.
• 
  

Part 2

Considering the evidences available up to this point in time, describe in detail how you would go about investigating further, assuming you are Dr. Rudi or Dr. Suria, explaining what you anticipate at each step.

The tooth is the most valuable source to extract DNA since it is a sealed box preserving DNA from extreme environmental conditions, except its apical entrance. This has prompted the investigation of various human tissues as potential source of genetic evidentiary material. Moreover, when morphologically evaluated, even a single tooth provides valuable information regarding the individual to whom the tooth belongs.

If i were Dr Rudi or Dr Suria, i would first extract the DNA from the jaw pieces obtained from the scene and do a dental DNA fingerprinting. DNA fingerprinting or DNA profile are encrypted sets of numbers that reflect a persons DNA makeup, which can also be used as the persons identifier. i would extract the DNA from the pulp of the teeth as the pulp produced the strongest PCR amplification signals. There are a few approaches i can take to sampling dental source DNA such as crushing entire tooth, conventional endodontic access, vertical splitting of the entire tooth, horizontal sectioning and cryogenic grinding. 

 I will then proceed on to analysing my DNA samples. Similarly i have a few methods of analysing to choose from, including Restricted Fragment Length Polymorphism (RFLP), Polymerase Chain Reaction (PCR) methods, Short Tandem Repeats (STR) analysis and also Y-chromosome STR (Y-STR) analysis for sex identification. Once i get the results, i will cross check the missing persons' list to see if i can get a match and find out if the victims are in any way related to each other. this will further narrow down my scope.

I could attempt on facial reconstruction as well to find out more about the victims involved in this case. Facial reconstruction is the method of reconstructing the living face of an individual from skeletal remains to aid identification ! How cool is that ? :O
Watch the video below to find out more!

If soil and plant samples are available, I would run a test on them as well. By sending the samples to the forensic botany lab, I can get an estimate of the time since death of an individual, connect a suspect to a victim or weapon or determine that a body has been moved.

Part 1 : Murder Most Brutal !

Question 1

We have all heard of how Forensic Dentistry has helped in the identification of burnt victims and also victims with bite marks. Explain more about these and describe how is Forensic Dentistry could be useful in the identification of murder victims?

Dental analysis is an excellent way to collect evidence and solve crimes. This is because teeth is able to withstand fire that destroys all kinds of evidence, burn human bones to ashes & even melt copper and glass ! :O

At the scene of the crime, odontologists collect the skull or remaining teeth, which are taken back to the forensic laboratory for the postmortem dental investigation. X-rays are taken and if the jaw is completely intact and the dental records used to compare are recent, the job of proving a match is a relatively simple one. Dentists mark on a chart the position of missing teeth, crowns, bridges, fillings, caps, root canals and various other treatments during a patient's routine check-up. 

It is said that no two people has the exact same dental imprint ! Using bitemarks, forensic odontologists are able to take bite-mark impressions on the skin of the victims. By comparing many factors, for example matching for striations whorls, indentations, pitting and abrasions, with the help of computer-enhanced photography.

The physical characteristics of both the bite mark wound and the suspect's teeth include:

• the distance from cuspid to cuspid

• the shape of the mouth arch

• the evidence of a tooth out of alignment

• teeth width and thickness, spacing between teeth

• missing teeth

• the curves of biting edges

• unique dentistry

• wear patterns such as chips or grinding.

It can also be determined from the type of bleeding beneath the skin whether the victim was alive or dead at the time the bite mark was delivered.

The forensic odontologist simply gives evidence as a witness to injuries caused by biting and it is the method in which they choose to present evidence in court that convinces a jury whether a suspect guilty or innocent.

Isn't it amazing how each and everyone of us are distinct in our own ways and we would not be able to escape from our wrong doings or wrongly accused ?! :O 

Question 2

Is a male human skull different from that of a female? If yes, how?

Yes,a male skull is different from a female skull ;

Weight : 

• Male : Heavier 
• Female : Lighter

Size : 

• Male : Skull size is larger
• Female : Skull size is lighter

Bony Mass / Thickness : 

• Male : Thicker
• Female : Thinner 

Contour of the face : 

Female Skull

Male Skull

• Male : Overall length of the skull is longer , chin is bigger & protrudes more forward ; Zygomatic                    bones are thicker
• Female : Skull is rounded with the facial bones being smoother , jaws mandible & maxilla are smaller. 

Forehead : 

• Male : Slightly sloping or receding 
• Female : Forehead is vertical 

Vault of the skull :

• Male : More rounded and prominent
• Female : More flattened

Supraorbital Margin : 

• Male : More rounded
• Female : Sharp 

Frontal bone  : 

• Male : Brow ridges are well demarcated.
• Females : Smooth, more vertical frontal bone. 

Mastoid Process :

• Male : Larger Mastoid process

• Female : Smaller Mastoid process

So, this is just a video of us doing a simple comparison of a male and a female skull. Hopefully it helps to understand better ! Enjoy :)) 

Question 3:

From the story above so far, how many victims are there? Explain. 

From our investigation, we assume there is only one victim because there was only one skull discovered and we assume the pieces of bone come from the same victim.

Thats all for today ! Hope this has been informative :)

The investigators ;) hehe.

Stay tuned for more upcoming posts ! :D

xoxo,
Bright lights