Balancing Safety with Sieverts
October 21, 2015 4:45 AM   Subscribe

"In New York City, the police now maintain an unknown number of military-grade vans outfitted with X-ray radiation, enabling cops to look through the walls of buildings or the sides of trucks ... The NYPD will not reveal when, where, or how often they are used."
posted by tocts (45 comments total) 16 users marked this as a favorite
 
The terrorists really did win.

Hijacking a couple of planes. That's all it takes to send a country into a decades-long spiral of fear and paranoia and ready surrender of liberties in exchange for imagined security.
posted by escape from the potato planet at 5:00 AM on October 21, 2015 [51 favorites]


I see what you did there.
posted by fairmettle at 5:01 AM on October 21, 2015 [1 favorite]


I predict sales of lead wallpaper will soar in Gotham.
posted by Bee'sWing at 5:03 AM on October 21, 2015


Is there anyone left here (whose uncle isn't a cop) who considers the NYPD to be anything short of a permanently occupying army?

I mean "left" since like the labor disputes in the 30s.
posted by griphus at 5:12 AM on October 21, 2015 [9 favorites]


The technology in question. The idea is to use backscattered x-rays, because low-Z (i.e. organic) materials have higher scattering. This has a bunch of technical advantages over traditional x-ray imaging: Since the detector is placed next to the x-ray source (not accross from it, as in a transmission machine), you can put both on the same moving platform (i.e. this van) and get a very small, portable system. You can also make do with a smaller x-ray source, since you don't need to penetrate the entire thickness of the object to get an image on the opposite side - a small source is good, because it means again more portability and also lower overall doses (not that people using this particular application seem to care very much about dosimetry).

There's an obvious disadvantage as well: since low-Z materials show up bright on a backscatter image, you can hide your contraband behind materials like plywood instead of cumbersome lead or steel.
posted by Dr Dracator at 5:13 AM on October 21, 2015 [3 favorites]


The NYPD Is Using Mobile X-Ray Vans to Spy on Unknown Targets

Has anyone ever seen Eraser? hmm....why is this familiar?
posted by Fizz at 5:18 AM on October 21, 2015 [2 favorites]


Could you (with affordable equipment) detect when these scanners are focused on you and automatically trigger an alarm or take pictures of the offending vehicles?
posted by pracowity at 5:19 AM on October 21, 2015 [4 favorites]


Is there anyone left here (whose uncle isn't a cop) who considers the NYPD to be anything short of a permanently occupying army?

Yes.
posted by escabeche at 5:39 AM on October 21, 2015 [2 favorites]


Aunt?
posted by pracowity at 5:41 AM on October 21, 2015 [10 favorites]


The technology was used in Afghanistan before being loosed on U.S. streets. Each X-ray van costs an estimated $729,000 to $825,000.

You never seen so many bleedin' aerials. The man said their equipment could pinpoint a terrorist at four hundred yards.
posted by three blind mice at 5:57 AM on October 21, 2015 [15 favorites]


Interesting question as to whether this could be detected. The answer is 'yes', because obvious the scanner has to be able to detect the back-scattered X-rays and these will be much weaker than the ones that impinge on the target, so detection is possible, but whether it's possible cheaply... I'd think so. Photovoltaic cells respond to X-rays, but you'd have to know a lot more about the system as a whole and how PV cells actually react to that.
posted by Devonian at 6:09 AM on October 21, 2015 [1 favorite]


The specific thing the NYPD owns appears to be this AS&E product

They say this, which I believe: "Dose to Cargo: Less than 0.1 microSievert (μSv) per scan (equivalent to 10 microRem (μrem)), at an average speed of 5 km/h (3 mph) at a scan distance of 1.5 m (5 ft). Should a stowaway accidentally be scanned, the effective dose is well below the ANSI specified limit for accidental exposure and is equivalent to flying two minutes at altitude."

While there may be issues with how forthcoming they are, I don't believe there is a health risk here, and can imagine scenarios when it would be both useful to a organization like the NYPD to have such a device for completely legitimate purposes and its use wouldn't pose a threat to civil liberties.

The NYPD's radiation guy gave this talk last year which appears to have covered the technical aspects of the issue, though the presentations don't seem to be available.

Incidentally, he appears to be involved with the KU Astrobiophysics group, who do really very neat work and should be a metafilter post.
posted by Across the pale parabola of joy at 6:19 AM on October 21, 2015 [5 favorites]


I don't believe there is a health risk here, and can imagine scenarios when it would be both useful to a organization like the NYPD to have such a device for completely legitimate purposes and its use wouldn't pose a threat to civil liberties.

I have some suggestions:

1. Get a warrant from a judge every time it's used.
2. Record every time it's used in exigent circumstances.
3. Disclose statistics of its use to the public, like whether it found any terrorists or just petty criminals.
4. Allow third parties to study its impact on health.
5. Make it subject to oversight and justify its expense.
6. If it's used in a criminal case, don't lie about it to the judge.
7. Stop having so much contempt for the public and the Constitution.
posted by RobotVoodooPower at 6:29 AM on October 21, 2015 [93 favorites]


I don't believe there is a health risk here

Mostly agree, with proper use, justification etc. - after all, we're talking about an x-ray tube riding around in a van here: if this was a dentist, there would be some system in place to make sure it is used in a responsible manner. I'm sure AS&E has designed this in a competent manner, and hopefully the NYPD has procedures in place to use it safely but I can see how keeping things like that secret would be problematic.
posted by Dr Dracator at 6:46 AM on October 21, 2015


Assuming that it is possible to knock up a cheap detector and that it could be small and low-power enough, then the possibility suggests itself of packaging that with Bluetooth and linking to a report-to-public-server-with-mapping mobile app.

I doubt very much that would please the powers that be. I don't think it'd be illegal; I do think it could be made anonymous.
posted by Devonian at 6:48 AM on October 21, 2015 [5 favorites]


I doubt very much that would please the powers that be.

Yeah, but it sure would please this power that don't be.
posted by pracowity at 6:59 AM on October 21, 2015 [7 favorites]


1. Get a warrant from a judge every time it's used.

I would have to think that under Kyllo they couldn't use anything from it as criminal evidence without a warrant.
posted by ROU_Xenophobe at 7:40 AM on October 21, 2015


Use a drone to follow the van.
Or use Lidarcaine
posted by clavdivs at 7:43 AM on October 21, 2015


I think people are overestimating the potential for abuse here and the Atlantic's framing does not help. This is not an all seeing eye peering into people's houses from afar. This is a system designed to inspect cargo. It's only going to be useful for scanning things right next to it which are moving slowly relative to it. And it will have limited utility even at that.

You know how when you enter any courthouse or federal building in the country, you put your backpack through an x-ray machine? This is going to be pretty much the same thing. I suspect the likely use is to monitor trucks and passenger vehicles without people in them parking at/near/under places where VIPs (foreign heads of state, presidents, Beyonce) are present and there is tight security. Like in the NYC subway, you don't have to let them search your bag, but if you don't let them search your bag you can't ride the subway and you don't have to scan your bag at the courthouse, but you can't take it in if you don't. I guess I'm not convinced of the value of this, but neither do I feel that it is trampling on my rights or at least not more than my rights are already trampled.

In practice, like many big ticket items owned by local police departments bought with federal grant dollars (I assume), it is likely to sit unused the vast majority of the time and since the grant covered purchase and maybe a few years of support, after that go completely unused.

As far as detecting its use, this puts out so little radiation in such a short time, you are not going to be able to detect it with anything cheap or small.
posted by Across the pale parabola of joy at 7:56 AM on October 21, 2015 [1 favorite]


this has been posted several times on reddit, and each time I'm just dang surprised that people don't see the ramifications of this. When the military started pumping military grade equipment into the police force, there were ramifications. This will NOT be used for a select few, specific, legal uses.
posted by rebent at 8:06 AM on October 21, 2015 [5 favorites]


Personally, I can't wait until my tax dollars go to pay the settlement for someone who rightfully sues the NYPD for misuse of this technology and wins.
posted by griphus at 8:07 AM on October 21, 2015 [6 favorites]


It's only going to be useful for scanning things right next to it which are moving slowly relative to it.

Every car that pulls up next to where's it's parked near a traffic light? Every person and building they slowly drive by? Every toll booth stop you make? Everyone in a certain part of town? Every car they pull over for missing tail lights or driving too slowly? Everyone who goes to a certain kind of club or listens to a certain kind of music? Every person they "randomly" ask to stand next to the van while they ask a few questions?
posted by pracowity at 8:08 AM on October 21, 2015 [9 favorites]


You need to move the van (at a pretty low speed) relative to the target to get a scan: You can't scan cars as you are driving down the highway (maybe with fancy speed-matching systems, but I doubt it), cars stopped at a traffic light, or cars you stop for some traffic-related reason, unless you don't mind being conspicuous as you drive the x-ray van along the target car.

(Also you're getting an image of one side of the car only, you'd have to flip it around and do another scan if you wanted to be thorough.)

You can indiscriminately scan cars parked along a street as you slowly drive by though , or in a parking lot.
posted by Dr Dracator at 8:23 AM on October 21, 2015


three blind mice: "You never seen so many bleedin' aerials. The man said their equipment could pinpoint a terrorist at four hundred yards."

METAFILTER JOKES EXPLAINED: This is a reference to the Monty Python Fish License skit.
posted by Chrysostom at 8:41 AM on October 21, 2015 [3 favorites]


Constitutional issues aside, how did that opening graf get past a copy editor? Saying "vans outfitted with X-ray radiation" makes no sense and it doesn't incline me to trust the writer.

(I'm on the ACLU's side on this one, but sheesh.)
posted by CheeseDigestsAll at 8:44 AM on October 21, 2015 [1 favorite]


You can indiscriminately scan cars parked along a street as you slowly drive by though , or in a parking lot.

Equipment to detect the google box truck guy and evict him from the parking lot?
posted by elizilla at 8:48 AM on October 21, 2015


It's safe! Non intrusive! Totally not a violation of your liberties and bears no resemblance to the state security vans of history/V for Vendetta. If you believe the company that wants to sell them and the police that want to use them.

Beyond that, what are the odds that 90% of the time or more these vans will be cruising along the streets of poor neighborhoods with high proportions of minority residents?
posted by Slackermagee at 8:50 AM on October 21, 2015 [4 favorites]


Across the pale parabola of joy, the difference between the examples you gave and the likely use by the NYPD is consent. That is where the high potential for abuse comes from. When you enter a courthouse, you knowingly pass through security. When you ship commercial cargo, you consent to certain screening procedures. When you simply exist, you are not giving consent to search by any technology, radiation or whatever. If they had consent to search already, why would they do it via an x-ray machine in a slow-moving van?
posted by nequalsone at 8:58 AM on October 21, 2015 [14 favorites]


I predict sales of lead wallpaper will soar in Gotham.

This site
says lead is at its lowest price in almost 5 years. The time to invest is now!

There are more markets for this other than just the obvious privacy products. Think of the prank/revenge/subversion applications. Thin sheets of lead could be cut in different shapes, coated in plastic, and either given a sticky or magnetic backing. What shapes, you ask? It could be anything - various sizes of guns or just about any 'suspiciously' shaped 2D geometric form. Want to get revenge on a enemy? Stick one inside his laptop bag, book, magazine, or those little pockets on the inside of the passenger doors. Want to give the operators of those vans something to find? Stick them to the sides of lamp posts, inside bushes that line parks, or on the trees that line the streets. Just because you've found yourself in a dystopian future doesn't mean you can't have some fun!

/sarcasm
/parody
/don't do this this is bad and probably illegal somehow
/If someone actually does this it's their own damn fault
/I can't believe I feel the need to write this disclaimer 'just in case', that in itself is kind of disturbing
posted by chambers at 9:10 AM on October 21, 2015 [4 favorites]


I would have to think that under Kyllo they couldn't use anything from it as criminal evidence without a warrant.

Take a look at the police playbook for shielding the Stingray from courts -- basically, lie about it and say it came from a confidential source.
posted by RobotVoodooPower at 9:10 AM on October 21, 2015 [2 favorites]


You know how when you enter any courthouse or federal building in the country, you put your backpack through an x-ray machine? This is going to be pretty much the same thing.

Except here, the courthouse comes to you!

Sentencing and punishment will commence as soon as the radiation machine gets warmed up.
posted by a lungful of dragon at 9:14 AM on October 21, 2015 [2 favorites]


I think people are overestimating the potential for abuse here and the Atlantic's framing does not help.

For decades, we've seen them abuse the tools they had at their disposal long before this machine was anything more than a fever dream: batons, tasers, guns, chokeholds, the ability to stop and search people, you name it. They've spied on Muslims gathering peacefully. They've tried to bully the Mayor for having the temerity to say he had concerns about how he would talk to his son about their conduct. They've gotten away with rape, assault, abuse. They've gone after people from within their own ranks who have tried to clean up the organization.

There is nothing -- nothing -- in their prior record that makes me think they won't abuse this new tool the first chance they get. In fact, I would be willing to bet they already have used it in shady ways.
posted by lord_wolf at 10:12 AM on October 21, 2015 [19 favorites]


Thin sheets of lead could be cut in different shapes, coated in plastic, and either given a sticky or magnetic backing. What shapes, you ask? It could be anything

Big letters affixed to the drywall reading WHAT SEEMS TO BE THE PROBLEM, OFFICER?

Smaller walls could just say HELLO NYPD.
posted by Spatch at 11:22 AM on October 21, 2015


We should just sick the vaccine phobic and chem trail people on them. Three birds one electron.
posted by srboisvert at 11:24 AM on October 21, 2015 [1 favorite]


Across the pale parabola of joy: "I suspect the likely use is to monitor trucks and passenger vehicles without people in them parking at/near/under places where VIPs (foreign heads of state, presidents, Beyonce) are present and there is tight security. [...] it is likely to sit unused the vast majority of the time"

Phew, that's a relief. Your suspicions about the likely use of these vehicles have really set my mind at ease. I'm sure glad to know that the NYPD is a well-behaved and professional department and not at all petty or out of control with a history of harassing, targeting, surveilling, and/or violating the civil rights of minorities and other undesirables. Thanks.

Sarcasm aside, it's not the radiation that's necessarily the most pressing issue for me personally, although I'd probably prefer third-party confirmation (i.e.: someone other than the vendor or the NYPD) that these devices are functioning to spec. It's my feeling that there's a near certainty that the NYPD will be using these devices to get around having to get warrants.
posted by mhum at 11:25 AM on October 21, 2015 [7 favorites]


I suggest they leave em' active 24-7 parked inside city hall, or maybe Goldman-Sacks. It'll help detect if anyone tried to smuggle any bombs into anyplace sensitive.
posted by jeffburdges at 1:51 PM on October 21, 2015 [2 favorites]


You should definitely concentrate on scanning the rich neighborhoods. They're of course the ones with the most to lose should hidden evil stalk the metropolis.
posted by pracowity at 1:58 PM on October 21, 2015




Dr. Dracator, you sound like you know more about this than me, but you also say you don't think people get much dose from this? I'm not so sure about that. Going backwards from the detector, what count rate and energy would it take to be statistically differentiated from background at some distance (inverse square law) accounting for attenuation of the side of the truck and the wall (both ways)? What kind of transmitted energy, when you need a 180-degree backscatter? This is no dental x-ray. I mean, I guess it could be safe, in the sense that a CT scan is safe, but that doesn't make it a good idea. The secrecy is a problem in that I have no way of evaluating that, because, no data.

Does the police department have to demonstrate compliance with all the NY State Department of Health's regulations for x-ray producing devices?
posted by ctmf at 7:54 PM on October 21, 2015


If the link the pale parabola of joy linked to earlier is correct, this thing dumps about one-fiftieth of one dental x-ray into the target.

To be clear: that doesn't mean I like it or anything.
posted by ROU_Xenophobe at 8:27 PM on October 21, 2015


This is the sort of thing that makes the tinfoil-hat brigade sound less squirrelly.
posted by bryon at 9:46 PM on October 21, 2015


Ooh boy, lots to say about this. For full disclosure I should mention I've done some (theoretical) work on similar devices, although intended to be fixed installations at ports of entry. Although it wasn't officially part of our portion of the job, we did speculate a bit about concerns like people not only putting together radiation detectors to detect our scanner, but wiring it up as a detonator for a sort of maximum-irony FU. And speculated about what sort of dose we'd be giving to, say, illegal immigrants hiding in a shipping container. Raising their lifetime-risk of cancer by some tiny amount would be one thing, giving them acute radiation sickness would be horrible.

So: having worked with (small amounts of) radiation both in the lab and in theory, and having worked with similarly-interesting and dangerous stuff in the lab and in theory, no, I have zero trust that these "safety limits" aren't a bit of masking tape stuck to a control panel with a line drawn in marker saying "safety line, do not turn past". And zero trust that some scanner operator hasn't said "this picture's too blurry, I'll just turn up the gain a little" and blasted people with much more than what's printed in the glossy brochure.

I mean, this is a world where we have documented proof of the sort of procedures the police use with stingrays and license-plate scanners. Trusting anything they said about these devices would fall under "fool me three times" at the minimum.

In a more broader sense that goes way beyond skepticism of the police, living life and reading history have taught me a general rule that if some system isn't audited, you might as well assume there's fraud in it. Cashiers swiping from the till, racial discrimination in hiring decisions, accidentally transporting real nukes instead of simulator devices; whether large or small humans make honest mistakes and feel temptations toward dishonest ones. It's not enough for a company to say "we're equal-opportunity" and train their employees on how discrimination is wrong. If they aren't using auditing methods that would actually catch discrimination if it were happening, they might as well be openly allowing it.

How often do they test and calibrate these things? Apparently medical x-ray devices in the U.S. have to be tested every 2 years, using something like this to look for leaks and dangerously-high levels, and film-based detectors for detailed and precision measurements. And of course their test records have to be available and auditable and the radiologists have to be well-trained in using their machines properly. Who gets to check the dose-rate testing records for these things?

Ok, a technical comment now: their brochure puts a happy face on how the absorbed dose is only 0.1 μSv at a distance of 1.5 m over a typical scanning time. What if they are using these things on the streets? What if a jaywalking pedestrian walks inbetween them and their target, right next to the scanner van? What happens if the techs inside don't hit the big red safety switch and turn off the beam because they were told it's not that much radiation? Going back-of-the-envelope with inverse square law scaling and reducing air absorption, a passing pedestrian at 10 cm instead of 1.5 m ends up with about 60 μSv instead. That's about eight times a dental x-ray. Still far from the worst problem with these things, but never let them get away with self-serving assumptions about their numbers.

P.S. on reflection, re: informed consent. If they're only using these in situations where it exists, like scanning a parking garage near some VIP event, then they would be perfectly ok with plastering these trucks with CAUTION: IONIZING RADIATION HAZARD. PORTABLE BACKSCATTER X-RAY DEVICE. STAY BACK 10 METERS WHEN RED LIGHT IS FLASHING. CONTACT 1-800-FEDS-ROK TO REPORT INCIDENTS. That they instead appear to be plain-white vehicles deliberately meant to be inconspicuous is the most serious warning sign they could carry.
posted by traveler_ at 10:48 PM on October 21, 2015 [9 favorites]


ctmf, I haven't done any calculations but they are claiming to conform to the relevant dose limits under their normal use scenario as linked by Accros the pale parabola of joy . I don't see reason to doubt this - they must have produced *some* paperwork if the government is buying this.

As traveler_ says, it's the accidental / improper use exposures one would be concerned about: if this was e.g. a fixed border portal, it would have safety measures such as hard-wired externally visible warning lights / audible alarms when the source is in operation.
posted by Dr Dracator at 11:43 PM on October 21, 2015




At minimum they should celebrate the purchase by parking em' in a circle around a dinner party for those involved, with the machine turned on while pointed inwards naturally.
posted by jeffburdges at 4:33 AM on October 22, 2015 [1 favorite]


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