Role of DNA in tracing Zainab’s murderer: report

KARACHI: The DNA sample of the suspect, Imran Ali, played a key role in nabbing him in the Zainab murder case, although, it remains a mystery why it took police two years to get to the suspect.

While police’s idleness may remain a mystery, locking in on the suspect through his DNA fingerprint is scientifically backed – but how?

To begin with: DNA (deoxyribonucleic acid)’s basic structural unit is nucleotides that contain a phosphate group, a sugar group and a nitrogen base. The four types of nitrogen bases are: Adenine (A), thymine (T), guanine (G), and cytosine (C), and uracil (U) instead of thymine in case of ribonucleic acid (RNA). The order of these bases determines the genetic code.

In simple terms, DNA is a molecule that contains the instructions an organism needs to develop, live and reproduce. These instructions are found inside every cell and are passed down from parents to their offspring– making each DNA sequence unique.

There is a little probability that two individuals on the planet can have similar DNA pattern.

In sexual assault cases, a DNA analysis increases the likelihood of identifying the perpetrator. By conducting a DNA fingerprinting test, genetic information in a person’s cells can be identified and evaluated.

DNA evidence can be collected from blood, saliva, sweat, urine, skin tissue, and semen – depending on where the assault took place and can be stored for years.

Talking to The Express Tribune, Chairman Council of Islamic Ideology (CII) Qibla Ayaz on where DNA analysis stands in Islamic law, who reiterated the council’s recommendations to the parliament in 2012 that while a DNA sample can be considered as a proof in a sexual assault case it could not be submitted as primary evidence.