Clever cops catch child abuser

This story on Quora tells how some clever cops used technology to catch a serial child abuser.

It’s an upsetting story, so be warned. The <self-censored> got 110 years in prison but that doesn’t really help the kids.

Yes and that is my beef with our revenge based justice system, it does not help the victims and in some ways teaches ‘innocent’ people to take pleasure at the misery of others.

Has the guy not been caught, he would be abusing endless new victims right now. It does help the kids because now a bunch of kids who would’ve been abused and had lifelong issues from it now get to be normal, happy kids because this guy is in prison rather than free and finding new victims.

As far as the article it is good but honestly not that impressive. They got his name off a pill bottle, that’s not too advanced. The fingerprint part was kind of interesting though.

I thought this thread was going to be about this guy, a pedophile who used the “twirl” tool in Photoshop to obscure his face in pics with his victims.

Why on earth would Interpol they reveal that they have the capacity to undo twirl? Why not just release the image on the left?

Why wouldn’t they?

In the first place, letting the public know that they have sophisticated methods of catching them is a good deterrent.

In the second place, the concept of a fair trial means presenting the evidence against a criminal in open court. They would have to show where they got the photo, and how they unscrambled it. They couldn’t keep it a secret if they wanted to.

Read the article - it’s not a court case, at the time they released this they had no idea who he was, and the image was released to the public to try to catch him.

“Deterrent”? All that’s going to do is deter other pedophiles from using this method to hide their faces. Since when has it been a good principle of cryptography to tell the enemy when you have broken their code?

They actually say in the article that they were torn by the conflict between releasing the untwirled picture to the public in order to try to catch him, and revealing their method. I don’t understand why they thought they had to reveal their method at the same time.

It helps all the kids he surely would have abused in the future, had he not been apprehended. And it helps some other kids by acting as a deterrent for other pedophiles, motivating them to avoid (or at least delay) becoming actual child molesters.

Point taken. But even so, I don’t sede any good reason to keep it a secret, and at least one good reason for saying it. The untwirled photo is *still *somewhat distorted. It lets the public know that his face isn’t really misshapen, it’s the effect of the manipulation.

Police procedures are different from military operations.

It is a good deterrent to say to potential criminals: you may know 100 ways to hide your face, but we know 500 ways to reveal it.

I’m highly skeptical of this. People who are abusing children are already so obsessed and driven by their lust that they are prepared to risk extreme punishment if they caught. Do you really think that the knowledge that the police can use high tech methods to reveal distorted images image would make them decide to just stop doing it? It seems extremely unlikely to me. I think it would just make them devote more effort to concealing themselves.

With virtually every behavior, motive is on a spectrum, and every hurdle you put up will deter some of the folks who would engage in the behavior. This applies to smoking (taxes), voting (IDs), and presumably child abuse.

Firstly, it is a basic principle of how deterrence works. Show people that they are likely to be caught, and some of them will stop doing it.

Secondly, no deterrent is 100% effective. it just needs to stop some people.

Third, it is likely that the images are made and distributed by professional pornographers, for money rather than their own paedophilia. Threat of capture could persuade them.

And fourth, deterrence has an effect on all crime, not just this one.

You’re discussing it as though I’m arguing against deterrence per se. Of course I’m not. In this situation, there’s a clear cost to any deterrent effect. So it’s a question of whether any deterrent effect is large enough that exceeds the loss from revealing a technique that might otherwise allow you to catch people.

The thing is, there exist ways to hide one’s face that are just impossible to undo. There is no deterrent then for hiding faces, just for using that particular tool.

That said, if you say and show you can undo it, that’s about the same as revealing the algorithm, as far deterrence goes. People don’t need to know how you did something to know you can do something. So there really isn’t much difference in showing you can untwirl a picture and telling people exactly how to untwirl it, in this case. You might as well.

The only way I can think to work around this would be to lie about how you got the original pic back, like maybe claim you used some advanced reverse image search that found it online.

I’m not following you. If you just release the untwirled picture to the public to see if somebody recognizes him, nobody (other than the perpetrator, who may guess) knows that you got the picture by untwirling.

I thought they undid the swirl thing back in the late 90s early 00s because they were trying to bust a Asian sex slavery ring and the tech firm that did it said it took two years and like a crew of 30 people to do it …….

That starts to make more sense to me. If they really couldn’t easily untwirl as a routine matter without dedicated huge time and resources to it, then it starts to look like a good idea to bluff that you can.

When I first heard the twirl story (sorry, no cite at hand, this was some years ago), it was presented as if the fact the guy used Twirl was a lucky break. It was done with Photoshop’s “Twirl” filter. The article I read pointed out that, unlike most of Photoshop’s other image-distorting filters, the Twirl filter doesn’t destroy any pixels. Instead, it just moves the existing pixels around according to an algorithm. On top of that, it turned out the guy used the Twirl tool’s default settings. So it was a simple matter to, with Adobe’s help, reverse the algorithm and just Twirl those pixels right back to where they started.