But there are some cases where there is only DNA. There is a double murder going to trial soon where DNA found via GEDmatch is the only evidence.

My fear is that planting DNA isn't something individuals are likely to do (thought it's not impossible), but something the state or large organizations are likely to have the resources to do properly. Corrupt LEOs. Corrupt politicians. It seems a lot easier than many alternative corrupt practices.

DNA also just ends up all over the place for innocent reasons. If someone gets murdered in a rental car that I rented last month, chances are my dna will be there. DNA evidence often struggles when it comes to temporality, as it can tell you who and where, but it can’t tell you when the evidence was placed there.

Historically there have been some pretty bad abuses in court over the accuracy and reliability of dna evidence, with some convictions that had to later get overturned.

Mixing/pollution of DNA samples in DNA testing labs (or faked DNA tests by unscrupulous labs) can also have some pretty bad consequences and have in the past.

Who needs corruption when you can have sheer incompetence?

https://en.wikipedia.org/wiki/Phantom_of_Heilbronn

DNA plants itself.

https://www.wired.com/story/dna-transfer-framed-murder/

That's a pretty good starting point. DNA will be falsifiable soon enough too which will render the whole idea of DNA as evidence of anything moot.

Would you feel differently if your child’s murerer was on trial?

Not trying to be gross, just trying to shine light on the idea that judges are in a difficult situation. They have to consider fairness for all parties involved.

That question is one of the pit falls we have to avoid to preserve any chance of avoiding a police surveillance state. "What would you allow if you were maximally emotionally impacted by a crime" is basically a blank check for 100% surveillance because inevitably any restriction on methods will eventually allow some crime to go unsolved.

Exactly this. At worst, you need to at least taper the emotionally charged question with the counter-point; "Would you feel differently if your child was falsely accused of murder because of genetic comtamination?"

Yep, to see how badly things can go when 'scientific' evidence goes unquestioned look at the mess that is stuff like bite pattern analysis which gets presented as scientific but has really bad actual statistics.

Justice can't just be about catching people it has to also weigh the cost of false positives and the effect that the methods have on society.

It's a constant issue with things like TOR, encryption, and alt currencies like BTC. They can do a lot of good for repressed people but they're also inevitably going to be used by people most people would agree are awful people to protect themselves from justice. If you're developing those tools you have to be ok with that just like we have to decide as a people where we're ok with the balance between preventing crime/catching criminals and personal liberty and privacy.

What if you were accused of a child's murder that you didn't commit? Perhaps it was particularly horrific and the police really want to catch the killer quickly to look good in the media. Your DNA matches the DNA the weapon, but match isn't the correct word - a better word is that it aligns / doesn't conflict. The situation gets worse once bigotry is added to the mix. I stand by my opinion.

> Would you feel differently if your child’s murerer was on trial?

Why would someone be less concerned with the reliability of the criminal justice system in that case? A low standard means it is easier for the government to let the guilty go free while making a show of punishing someone convenient.

There is a trade off between improving the probability of convicting the correct perpetrator and decreasing the probability of falsely convicting someone who is innocent. This tradeoff is essentially managed by the threshold required for a conviction. The legal system is generally not optimized purely for the first part of this trade off.

It makes sense that people who suffered from a crime would emotionally prefer more focus on a correct conviction at the cost of more false positives.

Surely the parent of a murdered child is massively compromised in judgement. Considering what they would think to be fair is like asking a madman what's fair, or rolling a die.

Isn't this Would you feel differently argument goes both ways? Would you feel differently if you killed someone and the police found you only thanks to such dubious from privacy standpoint practice.