Are You Mistaken? A Brief History of the Development of Molecular Forensics, and Why it Matters.
1983. Michael Jackson’s Thriller tops the US 200 Billboard album charts for 37 weeks. Alice Walker wins the Pulitzer Prize for The Color Purple. And Kary Mullis develops Polymerase Chain Reaction (PCR). PCR works by replicating short DNA segments. Amplifying them and producing a sample that is large enough to study, allowing scientists to produce DNA profiles from a single segment of DNA for the first time.
Just a year later Sir Alex Jeffreys introduces DNA fingerprinting, discovering a method that shows some regions in DNA contain repetitive sequences which are unique to individuals. This same year Rafael Ruiz is arrested and charged with first-degree rape, first-degree sodomy, first and second-degree robbery, first-degree sexual abuse. His conviction in 1985 is based on an inconsistent story, misidentification, and his blood type, which he shares with roughly 40% of the population.
Since Jeffery’s discovery there have been many advances in molecular biology and many methods of DNA analysis have been developed. Short Tandem Repeat (STR) analysis, and Amplified Fragment Length Polymorphism (AFLP) analysis to name two important ones. At this point you may be asking yourself, “Why does this matter?” To answer that I have a simple answer, Rafael Ruiz.
After his conviction in 1985 Rafael served 24 years in prison, during which time he was refused early parole because he would not confess to the crimes, they had charged him with. He was eventually released at the end of his sentence in 2009 and continued to maintain his innocence. It wasn’t until 2020, 35 years after his conviction that he was able to be fully exonerated utilizing DNA evidence.
The story of Rafael Ruiz is just one example highlighting the use of molecular forensics, and the importance of its development. If you are interested in learning more about its development and its applications, click on the link below. I also suggest checking out Rafael’s story, and other related work being done by the innocence project are also linked below.
Until next time,
Alanna
Forensic DNA analysis has vastly evolved since the first forensic samples were evaluated by restriction fragment length polymorphism (RFLP).
Rafael Ruiz’s Story: https://abcnews.go.com/US/dna-evidence-exonerates-york-city-man-1985-sex/story?id=68592919
Use of Molecular Forensics in Acquittals: https://innocenceproject.org/dna-revolutionary-role-freedom/









