DNA evidence being used to investigate old crimes

As a "forensic expert" going back 20 plus years I am totally familiar with the use of DNA to establish guilt (or innocence). DNA has indeed been gathered back that far, and further in some insances. The biggest problem was the ability to prove the credibility of it. In my field at the time (Image Processing), the biggest problem I personally had was to convince courts of the science. Had to prove that evidence was not being manufactured, just examined. I was not alone in this, and in actual fact played a very small role.

But back to DNA, the developing of it was called "Electro-Phoresus Examination" (sp) and used an electrical current to develop a pattern. The evidence folk knew they had something, just did not know what and how it could lead to a proveable science. So, even though they could not use it, they stored the samples away for future use. There is no actual statute of limitations on homicides. So, that evidence is now being re-examined in light of new technology. With some interesting results. In some instances convictions are being over-turned. In others, new suspects are being convicted.