A few years ago I wrote this in my book, Future Files:

“If you are charged with a criminal offence in the UK, a sample of your DNA is taken and added to a national DNA database where it stays indefinitely — even if you are subsequently acquitted. So far the UK database contains the profiles of 3,130,429 people, which is 5.23% of the entire UK population. In contrast the US DNA database contains just 0.99% of the US population, while most other national databases in the world contain the names of fewer than 100,000 people.

In theory this DNA fingerprinting is a very good idea, not least because the technology allows the police to create a DNA fingerprint using just a single human cell (taken from a print on a broken window for example). In the future police officers will carry handheld devices that can instantly upload these samples and test them against the database. These samples will then be used to create 3D photo fits of suspects, giving police officers accurate information on likely height, skin colour, hair colour and even personality type. Privacy campaigners are obviously concerned about this but the database and associated technology will be so useful that I’d expect the database to be enlarged as part of a national biometric identity card scheme.

Eventually until every single person in the country will therefore be listed “for their own security”, at which point adding some kind of GPS or other location tagging component would seem an entirely logical idea.  The problem, of course, with this is that once a government starts to view all its citizens’ as potential suspects there will be subtle changes to how everything from policing to law making operates.”

Why am I telling you this? Because there’s a good article in this month’s issue of Washington Monthly. I quote:

“Is DNA evidence, a forensic tool known for exonerating the innocent, being used to put them behind bars? That’s what lawyer and journalist Michael Bobelian argues DNA has a reputation for being virtually foolproof. And, indeed, when fresh DNA evidence is used to confirm guilt of suspects who have been identified though eyewitness testimony or other means, as was traditionally the case, the chances of hitting on the wrong person can be as remote as one in many trillions. But increasingly law enforcement agencies are employing DNA in a new way: to find suspects in cases where the trail has gone cold. In these instances, the chances of accidentally fingering an innocent person can be as high as one in three–a staggering fact that juries weighing such cases are almost never told.  ”

Link to full story in comments….