DNA Technology in Forensic Evidence

Michelle Leung and I just conducted a research presentation based on DNA technology applied in forensic evidence. Feel free to scroll through our Google Slides and refer to our presentation notes for further information on this breakthrough topic!

Slide 1 – Introduce your topic

Define what it means

  • Evidence obtained via scientific methods such as DNA technology, ballistics, blood testing for the purpose of establishing justice in the court of law
    • Should we make the definition simpler for everyone to understand? Something like “evidence obtained from scientific methods that is used in crime detection and justice in court”? Idk something similar
  • Can prove both guilt or innocence of suspects

Slide 2 – Give examples of uses

  • Comparing DNA of an identified suspect to that of DNA found on a crime scene
  • Comparing DNA found on a crime scene to that of past (and now public) offender’s DNA through a database
    • CODIS → Combined DNA Index System – a system that holds all DNA profiles across the nation
  • Comparing DNA found at different crime scene based upon DNA database information
  • Paternity tests

Slide 3 – Focus on one example & explain how DNA technology is specifically used

    • Testing the saliva of the identified person suspected for murder
    • Comparing that to evidence left behind on the murder scene that could be a direct link to the suspect’s DNA (ie: weapon, blood, fingerprints)
    • DNA Technology Used
      • DNA Extraction
      • PCR – Polymerase Chain Reaction
      • STR (short tandem repeats): two to five nucleotide-long sequences that repeat; different lengths/number of repeats sets people apart
        • PCR is used to amplify the DNA
        • Use electrophoresis to see how long or short the STRs are
        • Need very little of the sample, usually take 12 STR markers
        • Highly accurate because it’s very unlikely that two people would have the same set of STR markers/genetic profile
      • RFLP – Restriction Fragment Length Polymorphism
  • I found a specific case of the first DNA test that resulted in criminal charges that we could use an example:

Slide 4 – Find something extremely recent

A breakthrough in the use of technology that is related to your topic

  • Forensic Breakthrough: Unique Hair Proteins are Better than DNA in Human Identification
    • Article from Sep 2016 that talks about the idea that genetic information taken from hair proteins could provide better information & does not require DNA extraction
    • Although it is in the early stages of research it is believed to have great potential
    • Frequency of changes in amino acids is like the nucleotides for DNA – all about exploring proteomics, which is a newer field of study that goes beyond just genomics
    • A decent amount of hair is found at crime scenes  – could be very useful when there is no DNA to extract

Slide 5 – Pose an ethical issue or question raised by this technology for us to discuss

  • Should every human being’s DNA be put into the CODIS system (rather than just suspects or victims of forensic investigations) in order to speed up the process of DNA technology in forensic evidence? Or is that an invasion of privacy for the government to have all of our genetic information?
  • Think back to Cracking the Code of Life movie – Iceland debates whether or not they should have everyone’s DNA code.

Slide 6 – MLA Works Cited



One thought on “DNA Technology in Forensic Evidence

  1. Taylor, what an interesting investigation that you and your colleague did! I think it’s great that the having DNA technology to help with forensic evidence is very useful to catch the bad guys. I would in favor of having everyone’s DNA being part of the CODIS system. What a great crime deterrent, after all if you don’t have anything to hide then why would this be a problem?


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