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Comment by anigbrowl | Hacker News Reader

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 audio you know this isn't that hard.

I think what they really want to conceal is not the technology but its use in operation. I don't know what Chicago pays for the service, but Sacramento CA spends about $1m a year on it and Sac is a fairly small city. https://www.sacbee.com/news/local/article231997777.html

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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).

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.

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.

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

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