The superficial attraction of the policy is obvious. Anyone who watches CSI can relate to those forensics tests performed to Miami Vice-like soundtracks. Although this fingerprint analogy has floundered, Simon Power has his "tool to prove innocence as well as guilt" mantra down pat. Let's see how long that one lasts.
No Right Turn has an excellent summary of many worrying aspects of this change of DNA policy, with all sorts of source materials linked. Attorney-General Chris Finlayson's report has sounded a loud ping on BORA issues. The breach of unreasonable search and seizure is not trivial. The Bill of Rights guarantees, at least in theory, the sovereignty of self from the state. If this law is passed and instituted in its entirety, I can almost guarantee that it will result in cases to the Supreme Court, which the Crown will lose.
I have very serious doubts. I expressed some of them over at MacDoctor:
But there's much more, and you don't have to watch Dexter to get the implications. Consider the case of Arthur Allan Thomas, where a detective planted evidence in order to get a conviction. Consider the implications of an embattled police force, more concerned with keeping their work mates out of trouble than protecting and defending the public. How much effort do you really think it would take a cop with a vendetta to plant some hair, some used undies? What if was to get their cop mate off the hook?
Consider junk DNA. No-one knows what it does, hence the name. However, it stands to reason that it must be there for a reason, whether it be as an artifact or something other. I'm betting on other. With this great unknown in the balance, I'd prefer to future-proof against any future eugenics experiments by keeping the DNA testing regime in a very necessary small padlocked box.
It's a well-intentioned but ultimately dangerous intrusion on individual, ethnic, and human sovereignty. Just as Einstein wished he could go back in time and become a watchmaker and not a destroyer of worlds, or the dentist who conducted research into the pain mechanism and saw his work turned into a military weapon, so too Watson and Crick may well be damned for their discovery of the human code.
With all due respect to Simon Power, this tool is also a weapon. You don't know what it does. Put it down gently and walk away.