PART III: EVIDENCES VS SUSPECTED VICTIMS + VICTIMS' DNA PROFILING

The matching of Herman and Adi with the evidences above is inconclusive. Partly because we do not know how old exactly the father and son were. We can only prove that the victims were males, and were both more than 17 years old when they died.

The DNA profile showed evidence for a father and son. In addition there was DNA profiling pattern that matched one living twin (Tanya Rosilawati). With this, match the evidence to these victims who were earlier filed for missing persons. Explain your rationale.

What is DNA profiling?

Also called DNA testing, DNA typing or genetic fingerprinting.

The process begins with a sample of an individual’s DNA (this is typically called a reference sample). In this case, since the victims are deceased, the DNA can be obtained from personal items such as a toothbrush, razors, a hairbrush etc. This reference sample is then analysed to create the individual’s DNA profile. A number of techniques can be used for this (please refer to Part II: Question 5 under DNA profiling tests). The DNA profile obtained is then compared against another sample (in this case, DNA obtained from the skull / jaw fragments) to determine whether there is a genetic match.

How do we prove that the jaw and skull fragments belong to the victims?

Based on Question 5, we speculated that two of the adult jaw pieces belong to Adi and Herman Hartono and the child jaw belongs to Anya Suriati.

To confirm this, we extracted DNA from all the bone fragments and created DNA fingerprints of both the young male adults. We then obtained DNA from personal belongings of the suspected victims. If the DNA sample from the crime scene matches that of the DNA sample taken from the personal items, we can conclude that the bone remains actually belong to the individuals. 

Voila! Evidence 1 (Skull fragments and jaw with five teeth) belongs to Adi Hartono

Using the same method, another DNA comparison can be done for evidence 2 (jaw with three posterior teeth). If both DNA fingerprints match, we can conclude that it belongs to Herman Hartono.

How do we prove that the victims are father and son?

We all inherit our DNA from our biological parents. A DNA paternity test compares a child’s DNA pattern with that of the alleged father. The result of a DNA paternity test is either an exclusion (the alleged father is not the biological father), or an inclusion (the alleged father is considered the biological father).

For this profiling, Adi Hartono’s mother’s (Herman Hartono’s wife) DNA is required. 

The above picture is an EXAMPLE of DNA profiling.

On the left, the alleged father is NOT the biological father of the child, as the child’s DNA bands do not match that of the alleged father’s. On the right, some of the child’s DNA bands match with the alleged father and the rest match with the mother.

Observe the DNA bands carefully.

It can be seen that some of Adi’s DNA bands match with his biological mother’s DNA bands and the rest match with Herman’s DNA bands. It can thus be concluded that Adi and Herman Hartono are blood-related and that Herman is Adi’s biological father.

How do we prove that Anya Suriati is the owner of the child jaw?

Since there was DNA profiling pattern that matched Tanya Rosilawati, and identical twins have almost identical DNA, we can conclude that the child’s jaw remains belong to Tanya’s twin, Anya Suriati.