I would like to mention an actual case which took place in Quebec. An individual with mental health problems incriminated himself in a sexual assault case. Police officers focused their investigation on the suspect who had already served a sentence for sexual assault. It turned out that through DNA testing of this individual, it was determined his profile did not match that found on the victim. Police officers had to start a new investigation. This individual would have been convicted of a crime he had never committed. That would be an example of a success story for the data bank.
On April 28th, 2009. See this statement in context.