• UGI USER
  • Dec 19, 2022
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What is DNA fingerprinting and how does it help solve crime?

Why in the News

  • Delhi Police recovered bones from the Mehrauli forest area in connection with the Shraddha Walkar murder investigation using DNA Fingerprinting.

Origin of DNA Fingerprinting

  • DNA fingerprinting was first developed in 1984 by Alec Jeffreys in the UK.
    • No two people could have the same DNA sequence.
  • UK achieved the world’s first conviction based on DNA evidence in a case of rape and murder.

How is DNA fingerprinting done?

  • Each person’s DNA except for identical twins is unique.
  • By analysing selected DNA sequences (called loci), a crime laboratory can develop a profile to be used in identifying a suspect.
  • DNA can be extracted from many sources: such as hair, bone, teeth, saliva, and blood.
    • Samples may even be extracted from used clothes, linen, combs, or other frequently used items.
  • There is DNA in most cells in the human body: even a minuscule amount of bodily fluid or tissue can yield useful information.
  • Advanced DNA fingerprinting can make separate prints of various individuals even from a sample mixture found at the crime scene this is of help during gang rape investigations as each perpetrator can be individually identified.

DNA fingerprinting in India

  • At the Centre for Cellular and Molecular Biology (CCMB) in Hyderabad by 1988, Lalji Singh, who had spent the years from 1974 to 1987 in the UK on a Commonwealth Fellowship, had created DNA fingerprinting for criminal investigations.
  • In India, Lalji Singh, who died in 2017, is regarded as the originator of DNA fingerprinting.
  • The Kerala Police employed DNA fingerprinting for the first time in a case in 1989.
  • By the beginning of the 1990s, technology was being utilised to prove paternity, connect criminals, and identify victims in sensational crimes.
  • When semen samples from suspects were compared to vaginal swab samples in rape cases starting in the 2000s, the technology became standard practise.

Challenges with DNA fingerprinting in India

  • Using the appropriate tools is necessary to prevent the investigators’ DNA from contaminating those of the victims or suspects. Therefore, for the evidence to pass a court test, it is essential to collect samples from a crime scene using sterile tools and to store samples properly.
  • Lack of knowledge: State police personnel are not appropriately trained or equipped, despite the fact that central agencies like the CBI have the knowledge to ensure that crime scenes are protected and proper procedure is followed.
  • In the nation itself, there are no facilities for DNA fingerprinting. Only a few locations, including Maharashtra, West Bengal, Delhi, Hyderabad, and Chandigarh, offer DNA fingerprinting services.
  • Advanced practices in the technology are limited to the Centre For DNA Fingerprinting and Diagnostics (CDFD) in Hyderabad.