Final answer:
The use of DNA in criminal cases became possible due to discoveries in the mid-20th century that proved DNA is the genetic material, leading to techniques like DNA fingerprinting and genomic analysis utilized in cases like the 2001 FBI anthrax investigation.
Step-by-step explanation:
The use of DNA as evidence in criminal investigations became possible thanks to pivotal discoveries in the twentieth century that identified DNA as the genetic material. Groundbreaking experiments by scientists like Griffith and later by Avery, MacLeod, and McCarty laid the foundation by establishing that DNA, and not protein, is the key molecule of heredity. This scientific milestone paved the way for the development of DNA fingerprinting by Dr. Alec Jeffreys, which facilitated the retrieval and analysis of DNA from biological samples such as hair, blood, or saliva. Virtually every individual has a unique DNA sequence, which allows forensic experts to use these genetic markers in the identification process and in solving crimes. The first landmark use of genomics in a forensic case emerged in 2001, with the FBI's investigation into bioterrorism involving anthrax.
Moreover, DNA analysis has transcended its forensic applications and is used in areas such as genealogy, medical diagnostics, vaccine development, and cancer therapy.
Genomic analysis remains an invaluable tool in both legal contexts for evidence validation, as well as in broader scientific research and healthcare practices.