DNA The Golden Key of Forensic Evidence

DNA Deoxyribonucleic Acid Can be taken from cellular tissue or bodily fluids – Examples: hair, bones, blood, skin

DNA Fingerprinting Discovery 1984 Professor Alec Jeffreys discovers DNA fingerprinting 1985 DNA fingerprinting used for the first time to solve immigration and paternity cases 1986 first criminal investigation to implement DNA fingerprinting evidence 1992 DNA testing proves the innocence of Kirk Bloodsworth, who had spent two years on death row after being convicted of murder 1992 identification of Josef Mengele by DNA analysis of skeletal remains

What is DNA Fingerprinting? DNA holds the genetic instructions for all traits of an individual Found in the cells of every living organism – Unique for each species and for each individual – Scientists examine the unique sections to find a match between evidence and a suspect, victim, or witness Scientists take the DNA and make a “fingerprint” or picture for comparison

Why is a Person’s DNA Unique? DNA is a unique sequence of nucleotides inherited from mother and father – Bases A, T, G, C The base pairs carry codes for the traits of a particular species and individual The order of these bases are different for every sexually fertilized egg