Gunshot detection system transforms and raises issues (nytimes.com) |
Gunshot detection system transforms and raises issues (nytimes.com) |
$40,000-$60,000/sqmile/year is an extremely reasonable number. Chicago has 50+ officers per square mile, implying tens of patrolling officers per square mile; the fully loaded cost of a single police officer is six figures, with potentially explosive defined-benefit pensions and benefits just to make things fun.
Moreover, like in many big cities (read Peter Moskos _Cop In The Hood_ for details), the squad car patrol tactics used in Chicago do a terrible job of suppressing gun crime. Over a 24 hour period this holiday weekend, we had 25 gunshot injuries (god knows how many illegal firearms were discharged above and beyond that). The police can't be everywhere, and the patrol process keeps them mostly in rolling squad cars.
And obviously, the overwhelming majority of gun crime in the city of Chicago are concentrated in a small percentage of our square miles: Austin, Garfield Park, and (particularly) Englewood and Chatham. Which makes systems like this cost-effective to roll out, and, particularly, easy to pilot.
Panoticon here we come....
By my totals 17 shot on Sunday, 7 of them in 011. With 11 more starting at midnight to 0800 monday morning. The blackberry was ringing all night. 2 of the "victims" dead so far.
http://secondcitycop.blogspot.com/2012/05/not-one-shooting-s...
Note the scare quotes on "victims." Our informant continues:
The city should embrace all the violence and make it a tourist attraction. See if you can come to Chicago and make it out alive! Have tour buses go through the ghetto and stop at all the crime scenes. Get your picture with the body! Only 20 bucks. Better make it 30, 10 goes to the alderman of the ward the body is in. That way the visitors can get a small taste of how business is conducted in Chicago. As a special treat you may also get robbed at gun point during your tour. And if you want to see the indigenous population acting normally in its own habitat start using your Iphones where you can be seen. But you will be charged extra if you get apple picked! End the tour with specially trade marked Chalkie shirts with all proceed going to hire some real leadership at the FOP so we don't get screwed on our contracts. And give one buck from each tour to a special fund for the kids. ITS FOR THE CHILDREN!!!
God I love the Internets...
The scare quotes refer to gang shootings.
SCC tends strongly towards alarmism and, often, hyperbole. Your odds of getting shot in Chicago, even if you go to Woodlawn for Lem's barbeque, is extremely low. Unfortunately, your odds of getting shot if you're a kid living 24/7 in Englewood or Humboldt Park are unacceptably high. Also: lots of racist cops. Blue collar job.
I do have concerns about the use of conversations the microphones overhear but I know that in many neighborhoods events are not called in because the neighbor doesn't want the repercussions of turning in the local gang lord or his troops.
So, they could record conversations, but they won't for the time being. A classic example of using software to temporarily cripple the true capabilities of a computing device.
In the hands of DRM-wielding corporations, "defective by design" results in inconvenience and loss of users' freedom. In the hands of the surveillance state, the same technique results in a situation where citizens must simply trust the authorities to exercise restraint. Because the police could flip a switch at any time and record all sorts of conversations. Somehow I don't trust that the switch will remain un-flipped for long. And when it does get flipped, as it did in New Bedford, everyone will say it was just an accident.
Maybe, just maybe, we should accept systems like this as a necessary evil in certain cities where there's a lot of gun violence. Still, I don't like this. When it comes to the government, I'd much rather give them hardware that can't be unlocked "by accident" because there's nothing to unlock. The thing is, it's unrealistic to do that in all cases, and we have to hit a balance somewhere. Which is exactly why systems like this raise difficult issues.
Libertarians consistently make slippery-slope arguments when most everybody else is just happy that some immediate problem is solved. This line of debate is freaking getting old, and I'm the first person to do it.
The problem is that it always is a slippery slope. No bullshit. Changes take place over years or decades, so there's no single time you can raise an alarm. Right now it's gunshots. Next it will be car sounds -- estimating speeders and the conditions for traffic accidents. Then somebody will work out screaming. Then, perhaps conversations. And let's not forget that the systems will be justified by talking about the horrendous inner city. In actuality the vast majority of the time these systems will be used in places nowhere like that. When you read stories like this remember that these guys are selling equipment just like any other startup. You're getting their best pitch.
Big cities need this stuff, so it's a good thing for them. (Although I imagine we'll just start seeing a lot of silencers). What concerns me is that 90%+ of the time there's no crime being committed, save for discharging a firearm. So there's all these thousands of "criminals" discharging firearms that haven't been arrested before but could be now. Yay? Is it always a good thing with the grip of the state tightens, as long as we can point to something good coming of it?
Hopefully the cops will be so overloaded with gunshots they'll ignore the system and use it only for forensic purposes. But I doubt it. Instead I imagine we'll see these discharge numbers added to the crime reports for cities in an effort to secure more funding for even more police presence. Whether that's a good thing or not is debatable. There's obviously a real problem in Chicago and several other cities, but the rest of the country not so much.
Here's something from India. From times when weapons had to be carried secretly. https://en.wikipedia.org/wiki/Urumi
My forecast is that in the long run, bystanders will get less damage. But real murders get harder to investigate as there will be no gunpowder residue. And crossbow is easier to manufacture by oneself than firearm and that makes murder weapon tracking harder.
I'd rather pay for more cops.
These technologies are just used to put more distance between the corporate profits and accountability to the communities effected.
As a history lesson, dehumanizing intelligence services, preferring satellites and wiretaps to HUMINT, has crippled our capabilities. But it did enrich defense contractors, so it's all good.
I wonder at what point (in the adoption of this technology) it makes sense to invest in gun silencers.
I'm sure that silencers will still be detectable? They do make the gun softer but it's still noticeable if you know what you're looking for I'm sure.
Or maybe, they got sick of calling the cops and not having them come. If the gunshots are that common, it wouldn't be uncommon for the police to ignore the complaints as a high-crime district.
Now they can ignore the automated reports instead of the called-in ones.
I would imagine that a criminal could use a system like this to do a DOS of police presence and/or send them on a wild goose chase so they can commit a crime in another area. In other words they get police to scramble to 5th and Main and they have another team to break into a place a few miles away with a non-gunshot crime.
Also, as anyone who has experience with home or business alarm systems knows false alarms get to be a "boy who cried wolf" issue and you begin to not take them as seriously as you should.
Your example compares apples with oranges.
That would probably be a good thing for a competitor to create: a shot detection system that's designed to address civil liberty concerns. I bet someone on HN could do it.
Isn't that a total elapsed time of 2 minutes, 55 seconds?
But what if you shoot a person with a nail gun?
But I try to be pragmatic about it. Gunshots fired in urban areas are one thing that really is the business of the police! There's always some tension between law and order versus liberty; the trick is to find ways to trade the latter for the former at as high an exchange rate as possible. This system strikes me as having a very good exchange rate indeed.
It seems expensive.
Furthermore, I'm assuming they're not putting these in the middle of a Kansas corn field. Three people got shot outside of my apartment last year, I imagine they're going to prioritize that area over the upper east side.
I understand that making a recording of a phone call without notification is strictly disallowed in many states legislation? (eg http://en.wikipedia.org/wiki/Telephone_recording_laws#United...)
This technology also happens to be very useful for domestic counter-insurgence, something of interest to an economically polarized state during a time of economic transformation.
You could have one in every neighborhood. It might also be good in parking lots/garages.
EDIT: C'mon, downvotes? You do realize that vandalism will be a serious problem for this system.
Of course if the UAVs did start getting destroyed, it's not a stretch of imagination to think about how they could be protected...
There is another issue which is that a hand gun is a poor weapon for shooting down an aerial vehicle. A good marksman, or someone very lucky might do it, but the weapon of choice would be a shotgun. Shot guns on the other hand are not effective at range so in a street fight they aren't a good weapon (great for close quarters, poor for engaging at range).
So in a completely lawless sort of situation I could see teams of shotgun toting folks keeping the UAV population down but not in the typical urban setting in the US.
I sure hope so. My dream is to start a DIY / Open-Source Hardware project to create a drone that can shoot down the government drones and UAVs.
The real concern will be when governments start to identify their citizens by their voice signatures, and then use that to track their whereabouts.
Then imagine what is possible with such data. First off, you could use triangulation and advanced filtering between multiple microphones to be able to pinpoint the source of each sound and separate it out from the background. You could, as you say, identify individuals by their voices. You could track their wherabouts. You could monitor who they are talking to and when. You could learn so much about their lives by monitoring all of their conversations in "public". In the worst case scenario of the government turning into a police state this is a frightening level of surveillance.
I don't know how this would affect the legality of surveillance though.
And thanks to a recent heavy-hitter at the box office, the public has already had it decided for them that it's unethical! (Unless it's used once for a really really bad guy.) But apart from that this is an awesome system for its purpose. Keep it out of my home (they've already got phone-tapping for that anyway) and I'm fine with it.
This is no different from modifying the nude scanner at the airport to display a generic human form rather than the actual outline of your body. The machine still has the capacity to display what your private parts look like.
On the growth of such systems: it is almost inevitable that sensors end up getting placed everywhere. You have hundreds of sensors in your phone right now, many of them are uploading data to websites at various times.
Sensors will be placed on almost every utility as a matter of safety and efficiency. It is important to know when a pipe breaks or if there is a small leak in a gas main. Look up any given utility company and they will probably have some "smart" this or "integrated" that scheme in development.
There are cameras everywhere in most cities now, it is a matter of time before there are microphones too. Identifying who is where and who is speaking is a programming problem that has mostly already been solved. The two will be put together in the interests of safety and fighting crime. Someone might even invoke the terrorism word to speed up the process. Small-scale at first, in key places and important settings. Then rolled out across entire cities and states.
I am almost entirely visible to security cameras from the moment I step outside in the morning until I reach my office. Eventually, these systems will be integrated and process data effectively. The question is, what happens then?
You cannot come to reasonable conclusions about issues like this without seeing what's going on in the real world. This is not a math problem we're talking about; you can't sit around thinking and extrapolating and expect your conclusions to mean anything. It's like trying to run a scientific experiment without any data.
Do you know anything about criminal law? Do you know anything about the legal checks that are in place that prevent your doomsday scenario from happening? Are you aware of how evidence rules are applied in real cases? I'm sure you've read stories about the most egregious abuses, because they are the ones that pop up in the feeds that you read, but do you extrapolate from these that all cases are like this?
I say all this because I recently had the very eye-opening experience of serving on a juror in a five-week criminal trial. I realized that many of the prejudices that the technorati crowd has about the justice system are totally unfounded, at least for the case that I sat on. Our jury was not a clueless bunch of simpletons, our prosecutor couldn't get whatever he wanted by just saying "think of the children," and the judge was not an apathetic overworked bureaucrat who let anything slide.
What concerns me is that 90%+ of the time there's no crime being committed, save for discharging a firearm. So there's all these thousands of "criminals" discharging firearms that haven't been arrested before but could be now. Yay?
Are you really arguing that discharging firearms is a victimless crime? (edit: I'm talking about dense urban areas).
The slippery slope is already iced -- the systems are already being used to record conversations. But I guess that's ok, since it's just affecting those people on the wrong side of the tracks.
You've constructed quite an elaborate straw man ad hominem around me, so let's clear some things up. I do not watch Fox News or listen to talk radio (although there's nothing wrong with either). I do not have a feed that provides me with shallow-reasoned libertarian tripe. In fact, I scan more than 30 editorials and commentaries daily from sources as diverse as the foreign language press, Mother Jones, and the NYT. I also have many friends in the law enforcement community and think they do a great job. I am somewhat familiar with the system as it exists today. Nowhere near an expert, but not a theorist either.
Now that we've straightened out that bit, let's get to your argument. You cannot come to reasonable conclusions about issues like this without seeing what's going on in the real world.
This is exactly what I said: that real world tactical considerations are all that matter to some folks. The existing situation is that we have no gunshot detectors. So the question becomes, aside from structural political considerations, "Do such gunshot detection systems provide more societal value than harm?"
This might surprise you, but I'm all in favor of gun control laws for the inner cities. As population densities rise, the local government by necessity must take more control over citizen's lives. Note that I said "local government" and "by necessity". So the only problems I would have with these systems is whether they are being selected by the majority of the local people and whether or not they are deemed necessary by those people.
Are you really arguing that discharging firearms is a victimless crime? (edit: I'm talking about dense urban areas). No, I'm not, but since you brought it up, let's take a look at the real world data. According to the article, the vast majority of gunfire in a city doesn't cause death or major bodily injury. That looks pretty victimless to me. Personally, for a device that can cause bodily harm or injury to only one other person? I'm comfortable with an safety rate of around 99.9%. Others may have different preferences. The point here is that you can never have a perfectly safe conditions. The only question for folks to ask is how much risk is acceptable.
My problem is that we are making sweeping decisions for the entire country without realizing it. When you have a negative law, like "you can't own a gun", it only impacts the area where it is passed. But when you introduce new technology not covered by laws, especially technology meant to fix a social problem, you're setting a precedent for everybody. I'd argue that for 99% of the land area potential future gunshot detection systems will cover they will be neither wanted and controlled by the people nor deemed necessary by them. They'll become like automatic radar systems: another income stream and another intrusion into what used to be a mostly harmless affair.
One of the things that we don't talk about is how many laws are broken all of the time and it doesn't matter much to society at large. Things like the majority of these urban firearms discharges, people who lie to federal agents, speeding, or so on. To me, it looks like the purpose of these urban firearm discharge laws are just to have another crime to tack on to a suspect when sending them off to jail. I think the data shows that. But in either case, we have all kinds of laws, like speed limits, that are broken all of the time. Do we want to computerize our system of justice such that they are all followed all of the time? I'd give a vigorous "hell no!" to that idea. The system grew in complexity based on the idea that it was porous. You make it airtight and you'll have massive civil unrest on your hands. My opinion only, for what it's worth. The system of law we have evolved is not a system of morality or a way to lead your life. It's just a bunch of ad-hoc rules that are mostly consistent and worked by mostly great folks. But society couldn't function if you enforced 100% of all the laws all of the time. If you want to automate enforcement, we're going to have to get rid of a lot of legal code.
I wouldn't bet on this. Suppressors are highly controlled Federally, and completely illegal to own in Illinois (and Iowa and Michigan and a number of other states as well). You may think that doesn't matter to criminals, but most illegal firearms are purchased legally at some point-- not gonna happen for suppressors. And they aren't mix-and-match; you need a threaded barrel for your gun specifically. (There's a nice little scene in Goodfellas about this problem.)
But let's say you get ahold of one. You've got a line with a crooked Class 3 dealer in Indiana (this is someone who is also allowed to sell machine guns and grenade launchers) and he decides he's gonna risk his life by selling to a gang banger. Fair enough. So you get home, you load up your 9mm, screw on your shiny new suppressor, and go outside to take a potshot at some asshole you got beef with. Two minutes later, a couple of squad cars show up, lights flashing.
What happened? Well, you got your suppressor, but you're still using your same old bog-standard black-market ammunition. The can turns the hearing-damaging bang of your gun into a merely very loud bang, but it does nothing about the supersonic crack your bullet makes. You were quieter, but far from quiet; a ShotSpotter that was close enough easily picked you out.
If your dealer was looking out for you, he would have mentioned this, and recommended you switch to a subsonic ammunition. If he was really looking out for you, he'd also mention that this ammunition has significantly reduced range and stopping power, and probably does not have enough operating pressure to reliably cycle your automatic-- meaning you need to cock your gun every other shot like Jack Bauer. Sounds pretty much ideal for your inner-city gang fight, right?
And lest we forget, when the fuzz finally catches up to you, whether with the ShotSpotter or with good-old-fashioned police work, you are not going to get slapped with possession and sent upstate. As soon as that suppressor gets entered into evidence, with its nicely filed-down serial number, they're going to make a phone call, and the ATF is going to come to town with some serious Federal prosecution heat. They will hang you up by your toes until you tell them who sold the thing to you, and then they will find that person and make them severely wish that they had not.
So... yeah. Don't bet on it.
A more enlightened approach would be to ask why Chicago has so much trouble with gun crime, given that many other American cities have higher per-capita rates of firearm ownership both legal and otherwise.
One thing's absolutely certain: the real problem, whatever it is, will not be solved with digital signal processing.
At the time, these guys were dismissed as being totally wacko (my words, not the lecturer's). What kind of ridiculous slippery-slope arguments were these guys making, anyway?
Of course, all of these predictions did come true, it just took a long time. But when they were made it was all too easy to discount them as being far-fetched. This trend in public discourse continues to this day.
I don't understand your glib "digital signal processing" sentence. Technology won't help police forces become more effective? Strong disagree.
If criminals want to use gunshot noise to scramble police presence to a specific area, they can obviously do that without gunshot detectors. The point of detectors is to make it easier to follow up on ideopathic gunshots.
However, it would probably be more effort than it would be worth, so it is probably more a sci-fi / crime plot than a scenario that is likely to come up often.
If you would get a signal of multiple assault weapons firing at the same time, you would not send just one patrol.
It's not very likely. Unless someone manages to simulate gunfire accurately with a boombox or with a pipe and some layered gunpowder + lead shots.
Maybe. But I think it would depend on the particular department obviously and geography as well. You don't need all the police. You are decreasing manpower and ability to respond to other calls which can vary greatly depending on what else is going on. And this system might be installed in smaller towns with less backup resources as well.
http://secondcitycop.blogspot.com/2010/10/end-of-cabrini-gre...
And you must have loved this discussion of "Jared," "Brent," and their fellow Occupy bombers:
http://secondcitycop.blogspot.com/2012/05/bombers-pussies.ht...
Extremely low? Compared to what? What it should be? What should be your odds of being shot in a major city, anyway? San Francisco is extremely safer than Englewood, and earlier this year my wife and kids still found themselves in the middle of some kind of Norteno-Sureno shootout. They didn't get hit, though! So no harm, no foul.
Alarmist, certainly. Certainly alarmist compared to your normal Chicago sources of information, which as I recall insisted that the beaches on a certain day last summer were closed due to "temperatures in the '90s:"
http://secondcitycop.blogspot.com/2011/06/wall-of-lies-crumb...
It's a fact that I'm not a blue-collar fellow and I don't have a blue-collar job or a blue-collar family. And no, I don't think that if I were posting comments on SCC, I'd be quite as cavalier in referring to "the animal," "mutts," etc. It does get the point across, however.
The tools isn't Chicago's problem or else it would cause the same problem in ND. My cousin is alive because he had a shotgun on him when attacked by abandoned dogs. I don't blame the dogs ("how"). I blame the owner's who abandoned them ("why").
What if you stab a person with a knife?
It's off-topic. It was designed and built to detect gunshots from real guns.
[1] - I imagine a proliferation of cheap microwaves converted into portable battery-powered anti-electronics weapons. And how do you protect UAVs against that?
It's not a "police problem." It's a cultural one.
I think you're mistaking a clue bat for outrage. You sound like me when I was in high school: high on concern, low on experience. I don't know if you're young or not, but I'm basically saying what I needed to hear back then.
Also, my comment was not intended to offer unqualified support for this program. But if we're going to debate it, let's debate it in terms of the real world and not in a philosophical vacuum. The real world has checks in place like wiretapping laws and evidence rules. Are these perfect? Maybe not, but you do not even acknowledge that they exist.
> According to the article, the vast majority of gunfire in a city doesn't cause death or major bodily injury. That looks pretty victimless to me.
Gunfire in dense urban areas is harmful even if it does not hit anything: http://news.ycombinator.com/item?id=4036259
> To me, it looks like the purpose of these urban firearm discharge laws are just to have another crime to tack on to a suspect when sending them off to jail.
Suppose you lived in a high-crime area. Are you saying that it's totally fine with you if people drive down the street shooting guns as long as they don't hit anything? If you hear gunfire, how do you decide whether you are in danger or not?
> If you want to automate enforcement, we're going to have to get rid of a lot of legal code.
There's nothing in the article AFAICS about automating enforcement, just detection. I'm not sure how you're going to charge someone with discharging a firearm without an officer showing up. How would you even know who to charge?
Also, most peoples risk threshold is far below that for good reason. If you take a 1/1,000 risk of death per day (as a sum of all activity's) you have less than a 50/50 shot of living 2 years. On an hourly basis assuming 15 active hours a day 1/100,000 risk of death per hour = 50/50 chance of living 13 years. Really, 1/100,000 per hour is about the rational threshold for dangerous vs safe but 1/500,000 is closer to average.
As to speeding laws that's a side issue. With it's own set of arguments that has little to do with gun control.
If I'm walking down the sidewalk talking on my phone, overhearing my voice is not a violation of privacy.
But we're talking about recording your voice. Which I think is a violation of my privacy vs just listening to me passively - now that may not be enshrined in any law but then the law doesn't IMO [exclusively?] dictate what is moral.
http://www.hdcamteam.com/2011/07/10/report-cmos-ccd-cameras-...
If camera toting quadcopters on microphone equipped poles become common, I'd expect West Oakland gangs to start handing out high powered laser pointers to all the local kids…
I would say the most damning thing about using them for the purposes you describe would be the awkwardness of carrying around a shotgun that is that accurate and hiding it.
Of course the risks of firing a gun can be mitigated and controlled, but to do so, one needs a lot more rules and procedures (both on the individual and societal level) for guns than for forklifts and swimming pools. If you disagree with that, I'm afraid I (or, I suspect, some or most of the other people responding to you) won't be able to have a real discussion with you since our fundamental assumptions would then appear to be so far apart that we'd have to regress to a much more fundamental level and clarify those assumptions first before it would make sense to come back to the relatively high-level argument at hand.
I guess if it's illegal to do so, then a "Gunshot Detection System" has use. In the same way that Red Light cameras and Speeding Detectors serve a function in managing those laws.
There are lots of places in the Bay Area where you can safely discharge a firearm within city limits. At least I know I need to review the various city/municipal bylaws to see whether it's legal.
A gun locked up in a gun safe is surely safer than swimming pool. But a gun being shot in the backyard of a suburban home is definitely less safe than a swimming pool.
My neighbors live roughly 60 feet away from my house. If I went outside and shot a racoon that crossed my property, I'm pretty sure I would be in prison.
The Rural/Urban/Suburban thing is irrelevant - what's important is the safety of the discharge.
Regardless - the point I was trying (and clearly failing) to make is that there is nothing illegal regarding the discharge of a firearm. The crime is doing so irresponsibly and in an inappropriate location.
Could you please find me one example of a public space in a major metropolitan area where it is legal to discharge firearms? That is the issue here.
What? "Discharging a firearm" (shooting) is illegal in almost every situation in urban areas. If you think that you can go shooting at beer cans in, say, Central Park, as long as you make sure to only shoot at a downward angle and with a sand hill behind your targets, you're in for a rude awakening. It is unsafe to shoot in all but the most controlled circumstances (e.g. on a shooting range) in urban environments, and even suburban ones.
Are you sure about that? That doesn't jibe with the picture I've seen (http://i.imgur.com/XBevy.jpg) and doesn't sound optimal for an acoustic transducer.
I spent the last few minutes poking around StreetView looking for a photo of the units I'm thinking of without luck (the dates Google lists on their StreetView seem quite incorrect), but a hard, flat surface would be perfect for a sound transducer. It'd also be easier to weatherproof than something with microphones dangling outside.
In my city I know that they periodically move the units so it may be that they were moved when the pics were taken.
but a hard, flat surface would be perfect for a sound transducer.
I would be surprised if the mic was embedded in a flat surface, that would cause all sorts of diffraction problems for a surface that wasn't (effectively) infinite, especially since there is a lot of high-frequency energy in gunshots. I suppose they could try to equalize them out, but that seems like unnecessary work. But again, I haven't seen a (confirmed) transducer.
It'd also be easier to weatherproof than something with microphones dangling outside.
edit: actually I suppose the mic could be offset just an inch or so from the enclosure, that would be enough to reduce diffraction problems while not being noticeable from a distance. I'd love to see one of these systems up close. That problem has long since been solved with metal diaphragm mics, especially at the price points they're targeting. Microphones in airport monitoring systems last for years.
edit 2: some more searching indicates that a unit is actually made up of an array of mics. In that case, a flat surface would make perfect sense.
I'd like to listen to these lectures. Please try to remember what they're called. Thanks!
For one, while it's not 'hard' in the same sense that writing an OS isn't 'hard' (after all, it's a widely studied design, many have been made/written, there is much information available, so how hard can it be to write an OS, really?), it still requires tools that aren't that commonly available (a lathe, for example - how many people do you know that have one and would be willing to make a class 3 device with it?).
But also, the home made ones aren't that good. Yes, you can make a silencer for a .22LR good enough to not be heard several miles away when you're hunting at night. But those purposes are very different from silencing a caliber powerful enough to be used against humans; meaning at the least a .38 but preferably 9mm. Furthermore it's not so easy to affix silencers to hand guns and still have the gun be concealable, you have problems with semi-auto weapons to get the next bullet into the chamber, etc etc.
So, all in all, having to use silencers, even if they would work 100%, would still cause a significant barrier for perpetrating gun crimes.
And most of the market for weapons flow South; drugs flow north.
You're going to need a lathe, at least -- a machine shop would be better. Even if you copy an existing design (the science is mostly understood, but it's still easier to make one that doesn't work than one that does), the metallurgy is important-- you really need someone who knows what they're doing.
And that person had better hope that no one outside of the crew knows that they know what they're doing, because as soon as those off-brand suppressors start showing up on the streets, finding that person will become the number one priority for a number of very highly trained forensic experts. They really do take this stuff very seriously.
You could hear the firing pin hitting the cartridge (harder to hear than engine running) then you should hear the gasses exiting barrel somewhere around 0,001 second later. Then calculate doppler... Sounds kinda hard.
Also, how do you distinguish gunshots from background noise and triangulate the location of shots without first collecting raw audio from multiple devices and analyzing it?
"James G. Beldock, a vice president at ShotSpotter, said that the system was not intended to record anything except gunshots and that cases like New Bedford’s were extremely rare. “There are people who perceive that these sensors are triggered by conversations, but that is just patently not true,” he said. “They don’t turn on unless they hear a gunshot.” "
So apparently "the sensors", "They don’t turn on unless they hear a gunshot.". How, exactly, do they "hear a gunshot" if they're not (yet) turned on?
I suspect the truth is there's some software configuration that inhibits _recording_ of the sensor data until a gunshot-like event occurs (though if _I_ were designing this system there'd be at least a 30second or so buffer, so I could archive the sounds that if heard _before_ a gunshot as well as afterwards). But I'd hesitate trust that "configuration" to be particularly secure - much like the TSA "pornoscanners" - which in spite of claims of it being impossible, seem to be able to record images for the amusement of the operators and their friends…
I wouldn't be surprised to believe that some percentage of the HN audience might actually _believe_ that discharging a firearm is a crime, so I was seeking to inform them that it is not the act of discharging a firearm that is a crime. It's doing so in a negligent manner, or in an inappropriate location. Check your state/municipal bylaws.
Oh really? "Weapons from the north" are semi-autos. They have autos. (No, they're not convertible.) They get them from their military (which is supplied by the US) and similar sources.
A source that says "x% of traced" doesn't tell you how they decided to trace. (Hint - they have an agenda.)
It's a side point, but many semi-automatic weapons can in fact be converted to fully-automatic mode with drop-in parts. Makes sense; if you think about it, it's actually harder to make an auto stop firing after the first round.[0] Manufacturers do take steps to make the parts incompatible, but only with limited success.
Of course those drop-in parts themselves are considered to be machine guns by the ATF, and are thus absurdly expensive and hard to get ahold of. A fully legal and transferrable drop-in auto sear[1] for an AR-15, which is a few ounces of machined steel that lets you use the automatic M-16 parts, would have had to be made before 1986, and these days goes for >$5000.
[0] See http://en.wikipedia.org/wiki/Sputter_Gun . The ATF's original definition of a machine gun was a firearm which shoots more than once with a single trigger pull. Someone entirely too clever for his own good came up with the idea of making a gun with no trigger, which fired continuously so long as it was loaded. These were, for a brief period, completely legal to build and sell (although none were sold).
[1] http://www.quarterbore.com/nfa/dias.html . See also the Lightning Link, http://www.quarterbore.com/nfa/lightninglink.html which is literally just a couple of interlocking strips of metal. Cutting a strip of metal in that way is a Federal felony that can nab you >10 years even if you do not possess the actual rifle. They really do take this stuff very seriously.
In other words, it takes a machine gun to "convert" an "not machine gun" into a machine gun.
Yes, machine guns are easy to make. However, the claim is that mexican drug gangs, which have automatic weapons, are importing semi-autos.
I note that they are importing US made cars and using them. What should we do about that?
[1]http://articles.latimes.com/2011/oct/08/nation/la-na-atf-gun...
From the sound of it, if there's enough crime for these things to be cost effective then there are enough criminals around for somebody to get rid of the shot detectors.
I don't think the comparison to telegraph lines really makes sense. If telegram lines were used solely for reporting crime it would be a better analogy.
My guess (just a guess) is that the "criminals will destroy the sensors" concern is totally overblown.
Dispute the premise.
The head capos might have some smarts, in a cunning sort of way. But the footsoldiers and unaffiliated who get into gunfights on public streets? Not so smart. Disorganized American urban criminals aren't at the level of Al-Qaeda or the Mafia.
I think if the people having shoot outs are so brazen that they can do this and people aren't necessarily reporting them it's not a stretch to think that they will, just for fun, attempt to shoot down a UAV. Wearing a mask or course to protect their identity. Or try to damage it while it sits up on the pole with a rock etc. (Although I guess it could be protected from that fairly easily).
Another form of protection: they'd be less likely to shoot at something that shoots back. (Good luck making that legal for a private company though, even if the UAV managed 99% non-lethal accuracy!)
I think UAVs are impractical for other reasons (why not just put cameras everywhere instead of a fewer number of mobile cameras?), but I still don't think they'd be that much more a target for destruction than the electrical grid.
Doesn't have to be the thug shooting it down. Can be a pain in the ass bystander in the hood or someone with a baseball or rock. Have you ever seen kids who throw sneakers up over electrical pole wires in the inner city?
"they'd be less likely to shoot at something that shoots back."
Absolutely positively not going to happen.
I know of army units that have a machine-gun-the-RC-planes day for fun.
If only there was a device which could be affixed to the barrel of a pistol which could reduce the decibel level associated with the firing process... ;)