Article topic: The Role of DNA Analysis and Future Scope in Forensic Science
Written By
By Gauri Bhamburkar
Volunteer
Shivi Forensics
INTRODUCTION
• DNA analysis is a scientific process where we study the genetic code inside living organism. Every living organism has DNA, which carries information about how they grow, function, and look. By examining the unique patterns in a person or animals DNA, scientists can learn about their traits, ancestry, and even health conditions.
• In forensic identification, DNA analysis is used to help solve crimes by matching genetic material from crime scene to a person. Each person has unique DNA, like fingerprint, so when scientist find things like hair, blood, or skin cells at a crime scene, they can study the DNA to see if it matches a suspect. This helps investigators to identify who was at the scene or involved in crime. It is a powerful technique for proving some one´s guilt or innocence.
• DNA analysis methods have changed many more times. Every latest and advanced technique allows us for gathering more information, accurately or in short time. DNA profiling is well known tool in forensic for DNA analysis it can also be used for non -forensic purpose.
• This method of DNA profiling was developed by Alec Jeffreys and his team in 1985.
THE SCIENCE BEHIND DNA ANALYSIS
DNA is composed of four bases – adenine(A), thymine(T), cytosine(C), and guanine(G)- arrange in unique sequences that differentiate one individual from another. For forensic purpose, scientists focus on specific region called short tandem repeats (STRs) that vary significantly among individual. By comparing STR patterns from a crime scene sample with those of a suspect, forensic experts can establish a match.
ETHICAL AND LEGAL CONSIDERATION
The use of DNA in forensic raises ethical questions around privacy and consent. Collecting and Storing DNA profiles in databases must be done carefully to avoid misuse or wrongful identification.
THE POWER OF DNA SAMPLE
DNA database such as combined DNA index system (CODIS) stores profiles from convicted criminals, crime scene and missing persons. They allow forensic scientists to match DNA from unsolved cases to known offenders, leading to arrests and convictions.
TYPES OF DNA ANALYSIS/ TEST
• DNA profiling
• DNA sequencing
• RFLP analysis
• Genetic testing
• Mitochondrial DNA
• Y chromosomal testing
• DNA profiling
• Forensic DNA phenotyping
• Short tandem repeats
THE PROCESS OF DNA COLLECTION AND ANALYSIS
• Collection- DNA can be extracted from blood, hair, saliva, semen, skin cells and other biological materials.
• Extraction-The DNA is extracted from the sample using chemical technique.
• Amplification- DNA fragment is amplified with certain technique to create large quantities for analysis and experimentation.
• Profiling- The amplified DNA is then analyzed for STR patterns to create a DNA profile.
• Comparison- the DNA profile is compared against suspect samples or database like CODIS (combined DNA index system).
USES
• Criminal identification - DNA samples from scene of crime can be compared to suspects profiles to identify or exclude individuals.
• Victim identification – In case of mass destruction or unidentified remains, DNA can be helpful to confirm the identity of victims.
• Ancestral or genealogical analysis – Helps identify remains or individuals through distant familial connections.
• Paternity / maternity Testing - DNA analysis can determine family relationships, which is useful in custody cases or identifying missing persons.
• Sexual assault investigation – DNA from the perpetrator biological material e.g., semen can be collected and analyzed to confirm their involvement.
• Exoneration of wrongfully convicted individuals – DNA evidence can be used to clear those wrongfully accused or convicted of crimes.
• Wildlife forensic – DNA can be used to identify poachers or illegal traders of endangered species.
• Linking suspects to crime scenes- Biological evidence like blood, hair or saliva found at crime scenes can be matched to individuals through DNA.
CHALLENGES
• Sample contamination – improper handling of sample may lead´s to contamination, compromising the integrity of results.
• Degraded DNA – Environmental factors like heat, moisture, time can degrade DNA, making it difficult to analyze.
• Partial profiles – incomplete or mixed DNA samples can reduce the certainty of matching results.
• Technical errors – mistakes in DNA extraction, amplification, or profiling processes can affect accuracy.
• Cost and resources – high costs of advanced DNA analysis technology can be a barrier in some cases.
CASE STUDY
DNA analysis has been used in many well- known cases in India;
• Assassination of Rajiv Gandhi-
DNA profiling of disintegrated body parts led to the identification of the deceased and the perpetrator.
• Tandoor murder case-
DNA profiling was done on the burnt remains of the victim body in the tandoor.
• Pitchfork Killer –
This is the case where British geneticist Alec Jeffreys used DNA profiling to identify colin pitchfork as the perpetrator of two rape and murder case.
FUTURE OF DNA ANALYSIS
• Advancement in DNA technology such as next generation sequencing and rapid DNA testing, are pausing the boundaries of forensic science. these innovations promote faster, more accurate results, and broader applications in criminal justice.
• DNA analysis using AI which may faster and more precise in suspect identification.
• Handheld device for DNA sequencing at crime scene.
• Immediate suspect identification at crime scenes.
CONCLUSION
• DNA analysis/ DNA test has changed the world of forensic identification. Its ability to link individuals to crime or exonerate the innocent is unmatched by any other forensic method.
• As technology continues to evolve, the role of DNA in law enforcement will become more significant and important, ensuring justice is served in ways that were unimaginable just a few decades ago.
• This integration of science and law continues to protect society and uphold the truth. Continuous evolution in this field indicates that there are many more changes are going to takes place in this field.
REFERENCES
1.The role of DNA analysis in forensic science by Tony Borg.
2. Forensic DNA analysis.
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