Comment by a254613e | Hacker News Reader

Comment by a254613e | Hacker News Reader

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And if someone kills every memeber of your family, and they leave DNA behind, but police are not allowed to use DNA databases which WOULD find the person that commited the crime and they don't have a match otherwise (since we're already making assumptions that something will definitely happen)?

I mean this goes both ways. One thing I don't understand about this whole hate for DNA databases and matching relative's DNA on HN is... why?

Why does something that can help police catch criminals is such a bad thing? Because there are false positives? But those exist in pretty much all other investigation techniques. Cell phone positions, being seen on a surveillance camera few blocks away, having a similar car and being in the area, etc. Why is DNA so much worse?

In fact wouldn't adding more variables, such as DNA, to the existing techniques reduce the number of false positives as in "Oh yeah it's the same car, but there's 0% DNA similarity so no need to investigate further"?

Police "barging into your house with assault rifles and ballistic protection gear, and pointing guns at all members of your family" seems extremely overkill for a, let's say, 10% DNA match. And if they do really do that, then it's a problem with a police that needs to be addressed - not the DNA databases.

> why?

An ounce of prevention is worth a pound of cure. Better to prevent the emergence of corrupt and unjust institutions, than to try to reform or dismantle them after they have been formed. Institutions have inertia - once they reach a certain size and state, any change is difficult.

I want policing via consent. A police force that through diligent investigation comes to suspect someone of a crime and then acts on it. Let scene of crime DNA assist in showing a relation, or that the suspect may be male etc.

Yet a DNA database to trawl is the wrong answer. DNA is not a 100% unique match, it might not even be unique among everyone alive right now. It can degrade, techniques for amplifying very small samples are highly delicate and easily corrupted. DNA evidence at trial achieves that same undeserved halo effect as polygraph as the non-mathematical public and jurors don't understand any percentage confidences. It is far, far more influential than it deserves to be, even though unlike polygraph it has a real factual basis.

It should be one of multiple sources of evidence sought at trial, and should be barred from being sole grounds to convict.

A DNA and fingerprint database of convicted felons, accessible only to police and ports seems a reasonable compromise. A database of the innocent and not yet proven guilty? Fuck right off.

> why?

Because MY DNA is MY DATA. MINE! I own it, so I can do whatever I want with it, including not giving it to some weird company or whoever. Is that so hard to understand?

It's not me who needs a very, very good justification (and no, hypothetical criminal-catching doesn't cut it, because you'd have to prove me being a criminal first) to keep that data to myself, it's anyone else who wants to make use of it who needs a very good justification for that, ideally one that doesn't just depend on brute external force to "convince" me of consenting to someone else utilizing that data.

The problem with DNA is not that there are false positives but the fact that almost everyone thinks that there aren't.

> And if they do really do that, then it's a problem with a police that needs to be addressed - not the DNA databases.

I think the reasoning should go the other way: given that we know there are problems with the police that need to be addressed, we shouldn't have DNA databases until they are.

> Why does something that can help police catch criminals is such a bad thing?

Because that's not the only thing a DNA database can be used for, and "criminal" is a word whose meaning changes all the time.

People all over the world are being incarcerated right now for being born in the "wrong" race. DNA databases would make this much worse.

> Because there are false positives?

Yes

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