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.