The Law Commission is currently reviewing the law around the use of DNA in criminal investigations, and one of the issues they are looking at is whether to create a universal DNA databank holding the DNA of every kiwi:
A review of the law which governs how DNA is used in criminal investigations has raised the possibility of a databank which would hold every New Zealander's DNA.
[...]
The possibility of a universal databank which would contain the DNA profiles of everyone in New Zealand has been raised by the commission because it is being discussed around the world, although no country has one.
However, Ms Buckingham said that this was not an attractive option, but the commission felt it could not ignore the possibility of it.
She said it would not be a proportionate response and it would have enormous implications, potentially breaching individual and collective privacy rights as well as being difficult to establish.
"We felt we needed to talk about it rather than simply say we think it's not perhaps the best way to approach the issues of privacy."
What is there to fucking talk about? Its grossly intrusive, capable of handing the government vitally personal information not just about people's identities, but also their medical conditions - information they would find it very hard to get a warrant for even with individualised suspicion. We haven't let them create a universal fingerprint database, despite the obvious convenience for law enforcement, and this is so much worse. Throw in the potential for any databank to be corruptly privatised by a future National government, and its an idea that we shouldn't touch with a barge pole.
(If you're at all worried about this, the most likely target for a DNA datagrab is people's Guthrie Cards, which contain blood samples taken at birth from pretty much everyone, which are retained for no medical purpose in violation of basic privacy principles, and which police already use. But the samples are your property, and you can get them back: simply fill out section D of this form and post it away with a copy of photo ID. It doesn't even cost anything, because its your data, not theirs)
The problem isn't that we hold too little DNA data - but that we hold too much. The police can take it from anyone they arrest, regardless of the crime or whether a conviction eventually results, and they retain it indefinitely, in violation of basic standards around proportionality and unreasonable searches (they can also take DNA by consent, but given those data storage standards, you should never consent to it). According to the stats in the latest police annual report (p 147), they currently hold samples on 186,000 New Zealanders, and added about 15,000 samples this year. Statistics on whether these samples help gain convictions are "not captured nationally", in violation of statute. But regardless, they're retained for people who are never charged or convicted, and for far longer than they need to be on those convicted of minor offences. The DNA databank needs a purge, not an expansion.