DNA collection is now widespread

An article in the New York Times discusses how the collection of DNA has expanded in 19 states and the FBI.  Today these states are taking DNA samples of those who are arrested or detained but not convicted of anything. Since in some places this includes samples of juveniles, questions are being raised about whether this violates the 4th Amendment. 

But this past week a man was arrested in connection with a crime committed more than 20 years earlier because of evidence found at the scene. So there are certainly many pros to entering as many DNA samples as possible in hopes of closing cases. 

Are there reasons not to do it as well.  Of course. The American legal principle of one's being innocent until found guilty comes to mind.

However a cost/benefit analysis brings me personally to the side of sample taking. The one caveat is that the match must be made by a person highly trained in finding the sample and then matching it on the database. So long as no new scientifically proven evidence evolves to show that DNA is not unique to an individual, I do not seen reasons for opposition.

How do you feel about it?