by Connie Park
The days of “good old-fashion” detective work just got better! The advancement of technology in DNA testing has proven to be a powerful investigative tool for law enforcement and it has become an established part of criminal justice procedure. DNA testing has been utilized in identifying suspects of violent crimes, missing persons, and to exonerate innocent people who have been falsely convicted. There were more than 17,000 cases involving DNA evidence last year in the United States. DNA test results are common today in courtrooms due to reliability of the tests. DNA testing allows the application of science to law.
DNA is the chemical deoxyribonucleic acid, which stores the genetic code of each individual person. With the exception of identical twins, each person’s DNA sequence is unique. In addition to blood and semen, substances such as saliva, teeth, and bones can be sources of DNA. The listed biological evidence contains white blood cells where DNA is found. It allows us to analyze “invisible” evidence collected at crime scenes such as perspiration on a suspect’s clothing, skin cells on a ligature, saliva on a drinking glass or cigarette butts. After a DNA profile has been developed, the profile is entered into the
CODIS system (Combined DNA Index System), which is a national databank. CODIS is a computer network that connects forensic DNA labs at the local, state, and national levels. CODIS will alert the system whether or not there is a match of that DNA profile in the databank. In 2000, the DNA Backlog Elimination Act required the majority of all States to collect and test DNA of defendants convicted of homicide and sexual assaults. DNA testing has transformed the way we solve crime and handle criminal investigations, but just as importantly, it allows no room for any errors. It has helped in solving many difficult cases and has discredited eyewitnesses' statements and physical evidence recovered at crime scenes. Through the use of DNA technology and DNA databanks, homicide cases from more than 25 years ago have been cleared. Investigators are able to request DNA testing on biological evidence where testing was not performed or was unsuccessful in years passed. In addition, DNA technology allows to test old, unpreserved, and microscopic bits of substance that could result in an accurate DNA reading. In 1984, a 14-year-old female was found in an abandoned building sexually assaulted, strangled, and bound. A suspect was developed during the investigation but investigators were not able to file charges. In addition to an eyewitess's statements, the complainant was last seen alive with the suspect. Due to DNA technological advancements, biological evidence was tested and a suspect was identified and charged. Frederick Johnson was charged with capital murder and is awaiting trial. Kerry Max Cook, author of Chasing Justice and a guest contributor at Women In Crime Ink, was charged with sexually assaulting and murdering Linda Jo Edwards. After 22 years in prison falsely convicted, Kerry was exonerated by DNA testing that identified James Mayfield as the real killer. DNA technology couldn't have come soon enough.
