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

chicagoreader.com

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

#151

Post by droopyEyelids »

gpm wrote: post #128
llanowarelves wrote: post #84

Earlier quoted context omitted.

If true, selective enforcement is bad. But some minority demographics commit disproportionate (edit: violent) crime per capita so you expect some proportional scaling (more crime = more need for crime detection) if they happen to live in cities/areas where that's the case. (Usually big cities)

> Usually big cities I'm surprised to see this is somewhat true in the US. In Canada rural crime rates are higher than urban ones, but that trend doesn't seem to hold for the US (per sources below) Of course extrapolating from "average crime rate" to "location of hotspots" might be suspect in both cases... Stats Canada: https://www150.statcan.gc.ca/n1/pub/85-002-x/2019001/article... Bloomberg article with some nice g…

If you'll look past the unempathetic title of this website, and the nasty tone of the author, you'll see some of how violent crime clusters in Chicago (data visualization)

https://heyjackass.com

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

#152

Post by Null-Set »

toomuchtodo wrote: post #100
anigbrowl wrote: post #38

Earlier quoted context omitted.

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 d…

This would work to give some evidence for the accuracy levels of the automated parts of the system, at least for true positives vs false negatives, but doesnt test for how the system generates false positives.

A bigger problem is that this doesnt approach any of the process problems with the human moderated parts of the system. For that you would need cooperation from the law enforcement customer. The customer would need to make a request like "are you sure you didnt find any gun shots around this time and place?" and see how the company responds.

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

#153

Post by [deleted] »

cortesoft wrote: post #142
toomuchtodo wrote: post #100

Earlier quoted context omitted.

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 d…

That would tell you if it correctly detected gunshots... but it wouldn't tell you if it falsely reported certain sounds as gunshots, if it works in all weather, etc.

[deleted]

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

#154

Post by SilasX »

evan_ wrote: post #53
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…

If the police officer was lying about hearing a gunshot to perform an illegal search, or the police officer used the “I heard a gunshot” excuse six times a day, then that would be a problem.

Okay but I don’t think the argument here is that there was no “bang” sound, only that the company with technology for classifying bangs might not be perfectly consistent, which is still a higher burden than applied to a police officer investigating a bang sound.

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

#155

Post by n8cpdx »

randyrand wrote: post #98

> 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…

Portland, OR is moving towards potentially implementing ShotSpotter.

The population is 6% Black. The homicide victims are 50% Black. We have twice the homicide count of Seattle, or more homicides than Seattle and SF combined. Portland is smaller than both cities, so it is very concerning.

Unfortunately the licensing model for ShotSpotter is such that it is only deployed in the high homicide neighborhoods due to cost. I have to imagine the marginal cost of an extra sq mile is low.

I’d like to see a diversity discount or something so that it would be economical to put the system everywhere and dispel the racial bias issue. Or maybe charge per homicide or gun recovered instead.

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

#156

Post by esoterica »

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…

The magic box already exists, it's called people who call the cops to report gunshots every time they hear fireworks are a car backfiring.

If you think it's wrong for police to investigate a shotspotter alert because it might be a false positive then the logical conclusion of that line of thinking is that it should be illegal for the cops to show up to investigate when someone calls in to report gunshots, since those are mostly false positives too.

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

#157

Post by nickysielicki »

thethirdone wrote: post #119
nickysielicki wrote: post #70

Earlier quoted context omitted.

MLAT time-difference-of-arrival improves the accuracy substantially. Edit: not true, but can provide equivalent accuracy. https://www.flightradar24.com/blog/how-we-track-flights-with...

Your link does not support that assertion. It states that MLAT is used for planes without ADS-B and that it only matches the precision of ADS-B.

Sorry, was going off memory. Thanks for calling me out.

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

#158

Post by SilasX »

subroutine wrote: post #59
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…

The cop that heard the backfire would likely be called to testify that fact in court. If they fail to show up, and the arresting officer (a different cop) claimed they made a probable-cause traffic stop based on what the other cop heard, and that cop refuses to testify, the prosecution is going to have a bad time.

A better analogy would be, if you asked the cop how he decides it’s a gun firing vs some other innocuous cause, and his department refused to allow the records of his brain scans to be admitted into evidence to determine if he were perfectly consistent in going after gun-like sounds (assuming it were a department that had brain scans going on for officers on duty).

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

#159

Post by bergenty »

pxmpxm wrote: post #126
randyrand wrote: post #98

> 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…

Quoted post unavailable.

It’s not really that simple though. You can always go back less than 40 years and point out that street gangs were a response to police harassment. That communities were selectively devastated with targeted infusions of dangerous and addictive drugs. That there is a continuous pattern of profiling based on superficial attributes. A bad summer can ruin a person’s life, I don’t understand how we don’t expect generation abuse to do the same. Clearly the “sub Saharan level” life expectancy is not a racial attribute but contained within precise geographical boundaries in a prosperous country. You could say it’s purely cultural and if you wanted to be more edgy a “racial or genetic” failing, but really it’s the system that has deliberately and purposefully failed them and any current circumstance cannot be considered mutually exclusive of the very recent past, let alone the past few centuries.

For counter examples, look how long the richest and most dominant countries for the vast majority of human history— China and India — took to recover from a much less brutal form of dominance.

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

#160

Post by foerbert »

randyrand wrote: post #98

> 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…

That's predicated on their ability to help catch murderers as well as their inability to allow police to enforce other kinds of crime.

It's also possible for good-faith efforts to play into a feedback system that ends up resulting in racial injustices. They can even do that while doing other good things too.

Then you have the uncomfortable and terrifically subjective question on your hands of weighing the costs and the benefits - both now and into the future.

I don't think you can dismiss this as being largely about race, nor dismiss it as irrelevant to race.

In some ways, it'd be easiest if it doesn't work. That way the questions get real simple.

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