DNA testing is 99.99 % accurate. It has helped identify unidentifiable remains. In cases where a child was abducted and found years later, dna testing can confirm the identity. Dna tested from crime scenes are entered into a database that can be used to assist law enforcement in their quest to identify criminals. The database is secure, and access is limited. It helps solve cold cases, and post-conviction testing has been proven to save lives and money. It is used similar to a fingerprint.
There is one thing that DNA helps with when it comes to the CJ system. Its that DNA is completely unique to every single person and it holds weight when used for Criminal Justice. You can have all these facts and details saying that one person is guilty, but DNA can change everything if it proves the opposite. It is the one single true fact that can not be made up.
DNA testing adds to scientific evidence in many cases. Had DNA science been more advanced in previous decades, perhaps convictions and trials would have turned out differently. DNA isn't the end-all, be-all solution to determine guilt or innocence. However, as forensic science increases then the criminal justice system improves markedly. Part of that forensic arsenal includes DNA testing.
Scientific evidence is, on average, far more reliable than witness testimony for many crimes. While it is not a perfect solution, DNA evidence can help seal or undo a case. Look at how many people were once convicted of a crime and then late exonerated by DNA evidence that proved they were not responsible.
Prior to DNA testing, people were imprisoned based on witness testimony and evidence, even if it was circumstantial. Since DNA testing has been introduced, there have been many prisoners who have been released from prison because it has been determined that they could not have committed the crimes they were accused of. DNA testing beats out witness testimonies and circumstantial evidence every time, and many men have been freed because of the implementation of it.
DNA testing has brought many improvements to criminal justice system. In some cases now they can find the criminal that they could not find in the past. DNA testing provides more ways to find the people who committed the crimes. It could be as simple as a piece of hair left at the crime sight and from that could lead them to the criminal, its incredible.