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ShotSpotter requests to be held in contempt rather than disclose its methodology

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Re: ShotSpotter requests to be held in contempt rather than disclose its methodology

#91

Post by scottlamb »

HWR_14 wrote: post #34
oneoff786 wrote: post #21

Earlier quoted context omitted.

There’s no way they have a legitimate secret sauce though… right? This doesn’t seem like a hard problem to do. Maybe some of this https://en.m.wikipedia.org/wiki/Independent_component_analys... Plus basic triangulation logic synced across a bunch of microphones?

It's phenomenally hard. Echos, indirect routing (bouncing off buildings), sound waves changing speed as they go through various materials (like a lens). It's a very hard problem. Heck, a truly calibrated surround sound system requires using a microphone to measure the volume in place.

> It's phenomenally hard. Echos, indirect routing (bouncing off buildings), sound waves changing speed as they go through various materials (like a lens). It's a very hard problem.

I doubt they've solved (or even have non trivial mitigations for) any of those subproblems, based on stories of how often they apply human "corrections". The portion they've implemented may be very easy to replicate.

Re: ShotSpotter requests to be held in contempt rather than disclose its methodology

#92

Post by sbierwagen »

nickysielicki wrote: post #55
solardev wrote: post #36

Earlier quoted context omitted.

I dunno if this company deserves that benefit of the doubt. Honestly, given their history, they probably just don't want to reveal that their entire business is snake oil, basically existing solely to make money by enabling law enforcement to create crimes out of thin air. If their science was sound they wouldn't have to resort to such tactics...

Why are you so skeptical of their technology? Look how accurate raspberry pi powered ADSB plane tracking networks are — and that’s a much harder problem: they have no funding, they’re doing triangulation at the speed of light, and they’re doing it without GPS clock sources. You could also point to the lightning tracker networks that work in roughly the same way. Given a few million dollars to outfit their nodes with…

I wonder if cell site networks could collect the same data. Cell towers are already mounted high up, have data connections and high precision GPS data. Adding a microphone array seems like it would be cheap and easy.

Re: ShotSpotter requests to be held in contempt rather than disclose its methodology

#93

Post by pxmpxm »

alasdair_ wrote: post #69
nickysielicki wrote: post #33

I don’t understand the argument here. Suppose shotspotter is deeply flawed and often confuses fireworks and car backfires for gunshots, how could that have any impact on this case or the legality of it? I don’t see it as any different than if a police officer is out patrolling, hears a car backfire, and confuses it for a gunshot. If he then detains someone as a part of his investigation and discovers some other crime…

Imagine I made a magic "crime detection" box that called the police each time a crime was "detected". Now imagine all it did was randomly pick a number from 1 to 100 each day and if it were a 1 or a 2, it "detected" a crime, giving probable cause to police to search people near the box. Now imagine I almost exclusively put the boxes in areas where black people without a lot of money lived. You could see this would be…

I would think the system will have difficult time materializing high rates of people that have been shot, which tends to be the chief metric for where it's deployed.

Re: ShotSpotter requests to be held in contempt rather than disclose its methodology

#94

Post by curiousllama »

daenz wrote: post #68
solardev wrote: post #5

(Not the OP) For background, this is the company that supposedly locates gunshot sounds in cities (and sometimes battlefields) by microphone triangulation. It doesn't work all that well and is selectively deployed in minority areas and is used by police to selectively enforce crimes, sometimes also altering the evidence. Vice did a few articles on them and the company tried to sue but had it tossed out. Shady all aro…

Top article on that vice link: >In Chicago, a government watchdog says Shotspotter alerts have only led to evidence of gun crime in 9 percent of cases. >fewer than 2 in 10 investigatory stops following ShotSpotter alerts resulted in the recovery of a gun 9% actually seems like a lot? Considering that most criminals don't stick around after illegally discharging a firearm. And 1 in 5 resulting in the recovery in a gun…

Honestly, I'd be surprised if 9% weren't below the rate from random searches. It's tragically quite common - and, to a point, quite rational - to carry a gun in some neighborhoods.

Re: ShotSpotter requests to be held in contempt rather than disclose its methodology

#95

Post by jchw »

daenz wrote: post #68
solardev wrote: post #5

(Not the OP) For background, this is the company that supposedly locates gunshot sounds in cities (and sometimes battlefields) by microphone triangulation. It doesn't work all that well and is selectively deployed in minority areas and is used by police to selectively enforce crimes, sometimes also altering the evidence. Vice did a few articles on them and the company tried to sue but had it tossed out. Shady all aro…

Top article on that vice link: >In Chicago, a government watchdog says Shotspotter alerts have only led to evidence of gun crime in 9 percent of cases. >fewer than 2 in 10 investigatory stops following ShotSpotter alerts resulted in the recovery of a gun 9% actually seems like a lot? Considering that most criminals don't stick around after illegally discharging a firearm. And 1 in 5 resulting in the recovery in a gun…

Well, I'm a layperson to anything related to criminal investigation, but this is a little concerning to me.

If you're in a particularly crime ridden area, my concern is how many of those 9% are the right evidence against the right person. It's pretty terrible if all it took to nab the wrong person was shoddy evidence from a shady and secretive company that is accused of having manipulated the evidence in the past. It is still quite terrible even if it's often correct, because that makes it much harder for someone who is innocent to do anything about it.

Still, it's possible that the numbers Vice is showing does not demonstrate the problem.

Re: ShotSpotter requests to be held in contempt rather than disclose its methodology

#96

Post by sbierwagen »

userbinator wrote: post #42
SV_BubbleTime wrote: post #19

Earlier quoted context omitted.

Quoted post unavailable.

I read the comment you're replying to as being satire/sarcasm, given how outrageous it is.

I read it as referencing the never-enforced firing pin microstamping law that California passed in 2007: https://en.wikipedia.org/wiki/Microstamping

Re: ShotSpotter requests to be held in contempt rather than disclose its methodology

#97

Post by renewiltord »

Laundering police positions is a pretty profitable industry. I think once I have my American citizenship, I'd like to give it a shot. The small-time stuff like police dog training[0], etc., and the obvious stuff like AI face recognition won't play. But there's a lot of stuff like this that can be relatively decent business. Everyone who could prosecute you is sort of on your side, so you're safe. And it has a naturally monopoly-esque situation since every time you play along you build a trust that you have their back.

Ideally, I'd like to replace police dogs to give police probable cause. Policing is a huge industry in America, and it's not realistically going to be reformed because there is also a lot of crime in America, so it's a lasting business.

I'm mildly worried someone else will get there first. But we'll see. I have a couple of ideas.

0: Though if you could run a large-scale single source of training with some sort of certification program, that would work. Dogs are a fantastic laundering device, but I don't like that it linearly scales cost to add more. You can force recurring revenue by getting "periodic retraining" into the process, which will play really well with everyone.

Re: ShotSpotter requests to be held in contempt rather than disclose its methodology

#98

Post by randyrand »

> selectively deployed in minority areas

God this phrasing gets so annoying. If white neighborhood residents were being murdered in their streets, you really don’t think they’d put these devices there? Residents would be itching for them!

It’s about catching murders - putting these devices in places with the most gun violence.

Having police catch murderers is something we all want - rich neighborhoods included - and something that takes resources and effort to do. It’s something that we are privledged to have, compared to many other places in the world that just let poor people kill each other without legal recourse.

Good people in these neighborhoods want policing. I have a friend in Humbolt park, and he practically has PTSD from constant gunfire. You think he doesn’t want these devices?

Bad correlations ad nauseam.

Re: ShotSpotter requests to be held in contempt rather than disclose its methodology

#99

Post by SoftTalker »

anigbrowl wrote: post #38
pseudo0 wrote: post #8

Earlier quoted context omitted.

Would results of discovery be public record? If so, I could also see: 3) They don't want their "secret sauce" made publicly available. That would both open them up to commercial competition, and make their product less reliable in court, as anti-Shotspotter experts would start figuring out how to effectively argue against the product's methodology. In general I think technology like this should have to be fully trans…

They could ask for the information to be under seal to protect their commercial interests. The actual technology is not all that complex. Transient detection and triangulation by decorrelation from a microphone (edit: not microwave!) array. You could probably prototype it in a week if you leaned on an established FFT library. Obviously they would not want to reveal their source code and so on, but if you know digital…

Chicago Aldermen are no doubt getting a generous kickback on whatever they are paying.

Re: ShotSpotter requests to be held in contempt rather than disclose its methodology

#100

Post by toomuchtodo »

anigbrowl wrote: post #38
pseudo0 wrote: post #8

Earlier quoted context omitted.

Would results of discovery be public record? If so, I could also see: 3) They don't want their "secret sauce" made publicly available. That would both open them up to commercial competition, and make their product less reliable in court, as anti-Shotspotter experts would start figuring out how to effectively argue against the product's methodology. In general I think technology like this should have to be fully trans…

They could ask for the information to be under seal to protect their commercial interests. The actual technology is not all that complex. Transient detection and triangulation by decorrelation from a microphone (edit: not microwave!) array. You could probably prototype it in a week if you leaned on an established FFT library. Obviously they would not want to reveal their source code and so on, but if you know digital…

While true the tech is not complex, I believe the discrepancy is "how accurate is it and is the data being manipulated to fit a crime" versus "the data is accurate and leading to fair justice outcomes."

Wouldn't "red teaming" ShotSpotter solve for this to see how accurate they are? A team would perform controlled firings in known locations under various auditory scenes with the city's approval, and then request the data from ShotSpotter to see how accurate they are (without revealing you are performing an exercise). ShotSpotter then doesn't have to reveal their methodology, as their data provided from a blind test will reveal the accuracy regardless of how they arrive at conclusions. The system is either accurate or it isn't (with a measured level of confidence), and this can be tested for without ShotSpotter's consent (as long as they continue to provide data to the customer per their contract).

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