Hacker News Reader

Comment by yeetaccount2 | Hacker News Reader

I’m waiting on a court case with a fingerprint as key evidence for conviction, in which the defendant brings this up. Might not pass reasonable doubt muster, but what if somebody sold fingerprint forgery kits online that made it push-button simple? Just supply an image or two, run it through some ML to reconstruct the print, laser etch a latex glove or similar…

I wonder if you could use CRISPR or “lab-grown meat” techniques to do the same with DNA evidence…might be something that would get you a contract with the CIA/NSA.

View on HN

Why in the world would you need CRISPR or lab grown meat? Just sequence the DNA and send it off to a DNA assembly service. The price is a couple hundred bucks a pop. You don't have to replicate the entire DNA, just the segments used for forensic PCR.

(On a side note, the state of biotechnology and life science knowledge on HN is utterly deplorable, repeating buzz words does not reality make.)

And what is involved in the DNA sequencing? And the DNA assembly service will probably take record of the operation itself (it is not a common service).

In the context...

OP was referring to state level actors.

Interesting (I had not thought of that side), but it remains revealing. When there is reason to suspect that the case was manipulated it may suggest that that level of capability is involved. Or that somebody "rubbed a drinking glass" on the scene...

hahaha - Friend, this is a news website not a scientific forum. Relax.

I’m no biologist, just seems easier to “infect” blood with someone else’s DNA than to make it from scratch.

Most of the evidence that shows up at a court case is forgeable. Simply showing that a particular piece of evidence could be forged in no way proves that it is forged. You would need some sort of argument to prove your contention.

All evidence is ultimately forgeable. At some point a modern day Godel could prove that “justice” in a free society is mathematically impossible.

The law has to operate within a practical compromise and err heavily on the side of reducing false convictions.

https://www.techdirt.com/articles/20210312/19343046414/man-s...

That is an article I was reading today. I don't know what is wrong with America.

Or err heavily on reducing the release of the guilty, depending on the region.

> Or err heavily on reducing the release of the guilty, depending on the region.

This is antithetical to the concept of serving one’s time. Guilty people deserve to go free once their debt to society has been fulfilled.

I'm referring to what people select for with law.

https://en.wikipedia.org/wiki/Blackstone%27s_ratio

Does a law system let some guilty people got free to avoid incarcerating the innocent, or does it incarcerate the innocent to avoid letting some guilty people go free?

My opinion is to lean towards letting the guilty go to avoid incarcerating the innocent, but other people in other places can lean the other direction.

Sadly, "forensic science" is often not science at all. Much of it is barely an improvement on the techniques from the Victorian era. Altogether too much of it is an expert saying "these two samples look like a match" without a quantifiable metric. DNA evidence has made enormous leaps in the right direction, but even that requires a good chain of custody, good lab practices, and honest actors throughout the process.

'what if somebody ...' made SaaS service to upload pictures and overnight ship the fingertip.

It would probably cause a huge media storm. Then the politicians would "fix it" by replacing it with face recognition... (suddenly Face/Off is no longer science fiction)

As long as you can weather the storm, a storm is not the death of shady businesses. The shady facial recognition software that scraped social media for images got some bad press, and then just stayed calm and carried on.

For all of those outraged by the media storm, it is free advertising to those actually interested in the service. All of the pearl clutchers feigning shock and outrage over shady service mean nothing to the company providing the service, as these were never going to be their customers in the first place.

suddenly Face/Off is no longer science fiction

Didn't a woman in France already have a face transplant?

I don't think it was the type of transplant Face/Off was depicting, hers was very natural-looking but also visibly not a normal face.

I'd like to see Mission: Impossible type transplants, or even masks like the ones they use, for that matter.

The CIA's former Chief of Disguise says they very much exist and are used, with some limitations [1]. Her comment on the 3d printer making the mask: "What if I said we had it".

Of course that's not really surprising when you look at the kind of Halloween masks you can get if you are willing to pay [2]. I imagine if you could special order them to perfectly fit your head they would be very convincing to the casual observer and to software.

1: https://youtu.be/mUqeBMP8nEg?t=673

2: https://www.youtube.com/watch?v=Y32hdPV0L3k

Would make for a good Black Mirror episode.

Sounds like they’d get lots of subpoenas.

From the linked article, it sounds like that already exists in some form.

> Using several close-range photos in order to capture every angle, Krissler used a commercially available software called VeriFinger to create an image of the minister's fingerprint.

Considering the extremely dubious evidence that makes its way into courts, such as bite mark analysis, I doubt you'd get that much traction arguing about these scenarios with fingerprints.

https://youtu.be/hJ35ApLKpN4

It's already trivial - $500 consumer grade resin printers have sufficient resolution, and creating the model from photographs is super easy.

Same for facial recognition - you can do Mission Impossible style masks, and the most significant investment is in time spent learning makeup and wig work.

Biometrics are not secure, just like a vast majority of locks. All it takes is tools, knowledge, and motive to bypass them.

Could work for a digital intrusion, but for crime scenes there is dna

DNA evidence is overrated. People leave their DNA everywhere, so it's not that hard to get some and then plant it somewhere else.

The tests also have varying accuracy rates, but people misunderstand what it means. If the test is 99.99% accurate, that doesn't mean that there is a 99.99% chance that the defendant is the perpetrator. It means that in a region with ten million people, you've whittled your suspect list down to a thousand people. If you pick one of them at random there is only a tenth of a percent chance it was them.

This especially problematic when dealing with "DNA databases" because then with a large database you have a high probability of finding a false positive match and the true perpetrator might not even be in the database.

Yeah I always wonder when you hear like "99% DNA match!!". So like you confirmed the DNA is probably from a human?

The tests generally choose markers that tend to differ between different people rather than the ones that tend to differ between people and animals.

But even then, people use percentages as if everyone's DNA was independent. Which it isn't. Blood relatives have similar DNA.

The one thing DNA is really good for is excluding people. If you have the rapist's DNA and you accurately test it against the suspect's DNA and it doesn't match, it's not them.

Fingerprint recognition has been mainstream in consumer tech/iPhones for 8 years. Surely it would have already happened?

Sure. No one has ever faked a fingerprint to access phone of the partner or used a printout to trick facial recognition to see the latest mails. Today even little Kids fake fingerprints of their parents to buy some microtransactions.

Reply on news.ycombinator.com