Become a fan of Slashdot on Facebook

 



Forgot your password?
typodupeerror
Security

Researchers Say a Breathalyzer Has Flaws, Casting Doubt On Countless Convictions (zdnet.com) 170

An anonymous reader writes: The source code behind a police breathalyzer widely used in multiple states -- and millions of drunk driving arrests -- is under fire. It's the latest case of technology and the real world colliding -- one that revolves around source code, calibration of equipment, two researchers and legal maneuvering, state law enforcement agencies, and Draeger, the breathalyzer's manufacturer. This most recent skirmish began a decade ago when Washington state police sought to replace its aging fleet of breathalyzers. When the Washington police opened solicitations, the only bidder, Draeger, a German medical technology maker, won the contract to sell its flagship device, the Alcotest 9510, across the state. But defense attorneys have long believed the breathalyzer is faulty. Jason Lantz, a Washington-based defense lawyer, enlisted a software engineer and a security researcher to examine its source code. The two experts wrote in a preliminary report that they found flaws capable of producing incorrect breath test results. The defense hailed the results as a breakthrough, believing the findings could cast doubt on countless drunk-driving prosecutions.

Researchers Say a Breathalyzer Has Flaws, Casting Doubt On Countless Convictions

Comments Filter:
  • ...which is why (Score:2, Interesting)

    by Anonymous Coward

    They take blood now, and refusal is an automatic conviction. The breath thing is just to let them know if they need to go to the trouble of calling a phlebotomist to the scene.

    • They take blood now, and refusal is an automatic conviction. The breath thing is just to let them know if they need to go to the trouble of calling a phlebotomist to the scene.

      Depends on the the laws of your state, thankfully.

      Sticking a needle into your skin by orders of the "state" is a bit invasive.

      • Technically it's not a conviction. It is considered a violation of the terms of licensing. Under US law one cannot be convicted except by a jury (or judge if a jury is declined). In some states refusal is a separate crime, but again, not an automatic conviction.
    • Re:...which is why (Score:5, Interesting)

      by rogoshen1 ( 2922505 ) on Thursday May 10, 2018 @11:36AM (#56588342)

      FYI, if there's even a SHRED of doubt, always opt for the blood test. Especially considering things like mouth wash, or ketones can result in a false positive. As an added bonus, that extra time waiting for the blood draw means your BAC is decreasing.

      Thanks MADD, you co-opted the 5th amendment with your prohibition agenda.

      • Re: ...which is why (Score:2, Interesting)

        by Anonymous Coward

        Also, I would ask for an extra vial be taken for independent analysis (by my lawyer).

        Don't know if you can do that, but frankly, it seems right.

        • Also, I would ask for an extra vial be taken for independent analysis (by my lawyer).

          Smart move. There was a case recently (although I can't find a record of it), where a DUI case was thrown out because the person whose blood was taken was jailed and his possessions were stored, but his blood sample wasn't refrigerated.

      • Re:...which is why (Score:4, Interesting)

        by Anonymous Coward on Thursday May 10, 2018 @12:04PM (#56588606)

        Thanks MADD, you co-opted the 5th amendment with your prohibition agenda.

        You have no idea how true this is. In New Jersey, when they arrest you, they read this laminated card with a a detailed description of how and why you have no rights, why you must submit to a breathalyzer on the spot or automatically be found guilty as well as face additional (double) penalties for refusing, and how you have no right to consult with a lawyer before deciding. You are also not allowed to ask any questions or clarifications. If you have any questions, they simply repeat the card verbatim.
        In addition to the completely obvious unconstitutionality of it, they see no hypocrisy in how the state's official position is that you "consented" to the test, even though if the test does come up positive, that proves that your consent was given while you are drunk, which in any other part of the legal system means that you did not consent.
        Then of course there is the issue of how haphazardly calibrated these machines are, how wildly inaccurate they are, and so on.
        Even still, even when the prosecution can't prove probable cause, and even if they lose the evidences for 9 months while they jerk you around, with constant continuances, they still end up convicting 100% of the time. No jury BTW, just a judge who is buddies with all the cops.
        Meanwhile, if you are rich, you can just bypass it all as your expensive lawyer winks at the judge and you don't even lose your license.

        Our "justice" system is a complete joke.

        • Here's the entirety of what you say: "I am happy to cooperate, as soon as my lawyer shows up." For everything else, you no habla Ingles (Or Spanish either).
          • You'll be cuffed in the back of the car before you finish that sentence.

            • That occasionally happens regardless of whether you've done anything wrong or not, especially if you're black or an immigrant. Like every other unwanted but unavoidable interaction: be polite, be professional.
      • There is a correction factor added to compensate for the time since the traffic stop that considers the gender and size of the person. If your blood tests 0.079 an hour later, you're screwed. You can also be screwed at lower levels. Delaying is not in your favor. If you think you're going to be over the limit, refuse the test. If you think you're gonna be close, refuse the test. Only take it if you know you're going to pass.
      • FYI, if there's even a SHRED of doubt, always opt for the blood test. Especially considering things like mouth wash, or ketones can result in a false positive. As an added bonus, that extra time waiting for the blood draw means your BAC is decreasing.

        Also, ask for an atty present for any fluid draws...this can also stretch the time.

        • You don't just get to delay until you're sober - they have a formula for determining your BAC at the time of your arrest, even if you take the blood test hours later.

          • You don't just get to delay until you're sober - they have a formula for determining your BAC at the time of your arrest, even if you take the blood test hours later.

            ANYTHING you can do to help your case, you should do......a lower number after time, you're lawyer can explain/argue much better than a higher number immediately after arriving at the station.

            Formula or not, a good atty can argue more on your behalf the more you give them a chance.

            • ANYTHING you can do to help your case, you should do

              I would recommend NOT drinking and driving. There's zero excuse. Of course you could be pulled over or arrested for seeming drunk, but if you're not drinking, you're not going to be busted after the test.

      • Having served on a jury for a drunk driving case, I would not convict on breathalyzer alone. In the case, the guy failed around 8-10 roadside sobriety tests in spectacular fashion and was obviously impaired by his speech. (We had a body cam video). The lawyer’s argument was the roadside tests have a 25% false positive rate so there was a 1 in 4 chance his tests were false positive. Unfortunately, she put an engineer and economist on the jury and we pointed out that .25 to the eight is infitessmally sm
        • Bad figuring. You're only talking about 0.25^8 if the trials are truly independent. If they were all on one breathalyzer, it's reasonably likely that the breathalyzer was bad.

          • Bad figuring. You're only talking about 0.25^8 if the trials are truly independent. If they were all on one breathalyzer, it's reasonably likely that the breathalyzer was bad.

            Road side sobriety - the walk the line, close eyes touch nose, horizontal and vertical gazing nystagmus, etc. so they were independent tests.

            • As long as he wasn't convicted on the basis of bad math, I'm only mildly unhappy about it. I still don't like bad math, being a bit of a math addict.

              • As long as he wasn't convicted on the basis of bad math, I'm only mildly unhappy about it. I still don't like bad math, being a bit of a math addict.

                No. It wasn't bad math since each was an independent event, just a bad argument by the lawyer. I had no doubt he was guilty, based on all the facts brought up at trial. It almost seemed as if the cop was giving him a chance to prove he was sober by retesting him repeatedly but the guy kept failing them. I was amazed the lawyer made that argument when she let people on the jury who thought math was fun and would see the fallacy in her argument. Perhaps she hoped she could sway one jury member and get them to

      • Especially considering things like mouth wash, or ketones can result in a false positive. As an added bonus, that extra time waiting for the blood draw means your BAC is decreasing.

        That's a lovely trap for idiots. In my state if you get pulled over at the booze bus, and request a blood test it'll be done in about a minute. If you blow over the limit you get to sit down for 10-15min before re-blowing precisely to gauge if you're blowing a temporary false positive.

        And if you're relying on something to get you BAC down to pass the cops then behalf of the rest of the road users, fuck you you drink driving fuck.

        • This method of avoiding a false positive could be improved by the following:

          1. Two different machines testing
          2. Machines must be from different manufacturers
          3. Keep the delay and re-run mentioned

          Reasonable doubt relies on the notion that we have minimized statistical chances of error. This regimen may be tedious, but we can make sure the innocent are not caught up with the guilty. But yeah, don't be drunk behind the wheel. I have a little sympathy for the person on the very edge of the range, but none beyond.

        • I'm saying this as a moderate (at best drinker) -- the .08 limit is pathetically, laughably low in terms of being an ACTUAL fucking public safety issue.
          Driving before morning coffee, or while tired is almost assuredly more of an impairment.

          It's a political 'thing', and shows us *exactly* what a 'think of the children mindset' results in. I can think of only a few instances where the presumption of innocence and due process for being searched is thrown out the window. DUI checkpoints? What kind of Soviet,

          • I'm saying this as a moderate (at best drinker) -- the .08 limit is pathetically, laughably low in terms of being an ACTUAL fucking public safety issue.

            Nope, You're saying this as someone who either is an excellent functioning alcoholic, or as someone who is dangerously unaware of their own dysfunction. I'm betting it's the latter. There are a myriad of people out there who barely cope with the 0.05 limit that most countries have in place. There is a myriad of research that no consumption of alcohol what so ever comes without some form of measurable impairment. And there's daily statistics to show that even without impairment humans are causing enough prob

      • Modern machines can tell ketones from alcohol. And testing procedure to admit results into court is 2 tests at least 17 minutes apart while monitoring the subject to make sure nothing goes in their mouth. The tests must be in good agreement to be admitted into court. That takes care of things like mouth alcohol.
      • As an added bonus, that extra time waiting for the blood draw means your BAC is decreasing.

        Not necessarily. If you gulp down a few beers and quickly go drive, your BAC might be .04% when you get pulled over, and .10% later on.

    • by sjames ( 1099 )

      In some places they do. In others, the breathalyzer is treated as iron-clad proof with no need for further testing.

  • Not in Europe (Score:5, Informative)

    by Ubi_NL ( 313657 ) <joris@id[ ]l.nl ['eee' in gap]> on Thursday May 10, 2018 @11:28AM (#56588252) Journal

    In .nl at least, these breathalyzers are used by police to do a quick test only. If the result is positive, the suspect is carted to a police station where a much more accurate machine is used to determine the blood alcohol levels. Only that ladt number is used as evidence.

    I was assuming all countries had similar methods.

    • Same here in Romania.

    • Re: (Score:3, Interesting)

      by will_die ( 586523 )
      It really depends on the state. One major difference is that in the US taking of blood is consider unreasonable search so police have to show a reason or you have to volunteer to give it. Also in most US states the legal limit is higher than Europe. there are a few states that use the 0.05% limit but that is usually for minors. Everywhere else the limit is 0.08%
      In the majority of states you will require you to blow when stopped(where this machine looks to be used), that reading is worthless except to s
      • by tempmpi ( 233132 )

        A blood test is also considered a search that requires consent or a warrant in Germany. But there is always a judge on duty for quickly granting a warrant to allow the blood test, even if the suspect does not agree to the test. A positive breathalyzer is considered reason enough to grant a warrant.

      • Re: (Score:3, Insightful)

        you automatically loose your license

        Lose.

        they would of never been taken

        would've

        The inability to spell on /. seems to be higher than in my daughter's elementary school class....

        Yeah, yeah, I know. Spelling isn't important. Get off my lawn!

        • by Pascoea ( 968200 )

          The inability to spell on /. seems to be higher than in my daughter's elementary school class....

          The punctuation around here is horrible as well. Who uses ellipsis when not desiring to omit irrelevant portions of quoted material? And a period after ellipsis? The world we live in today, it's gone right to hell.

      • by Ogive17 ( 691899 )
        In the US, you don't get pulled over unless there is reasonable suspicion that some law was violated. I am also not aware of any state that charges someone based only on the results of a roadside breathalizer machine. Those results are usually used in conjunction with other sobriety tests along with visual accounts from the officer.

        I have a hard time believing many, if any, convictions are overturned. My opinion is people who were arrested at DUI checkpoints are the only ones with a case, as there was
      • This is about the "Alcotest 9510" it is not a roadside test unit, this is the final verdict machine that is at question.

    • I'm not sure if it's required throughout the US (it varies state by state). However, I think you can request it throughout the US.

    • I was assuming all countries had similar methods.

      All civilised countries do.

      It's amazing how many people rant about seeing the source code for breathalysers (in case there's some hidden DWB routine or something) while actually believing in field sobriety tests which are purely subjective and also totally fucking rubbish. Disclaimer: I can't stand on one leg for more than two seconds if I'm stone cold sober two hours & three coffees after waking from the best night's sleep ever.

      • >"It's amazing how many people rant about seeing the source code for breathalysers (in case there's some hidden DWB routine or something) while actually believing in field sobriety tests which are purely subjective and also totally fucking rubbish."

        Conversely, even an absolutely precise measure of blood alcohol is ALSO rubbish. It says nothing about how much an individual is or is not impaired.... unless you know THAT PERSON'S EXACT baselines. There are lots of very valid factors that can complicate ho

    • It's the same as that in Canada. We use the Alcotest 7410 as a roadside screening device and the Intoxilyzer 7000 to do the actual certified test. I assume most of the worlds works that way, but it wouldn't surprise me to find out the US has an asinine system in place to help the lawyer make a fortune. Already on this thread I'm reading about field sobriety tests and blood tests. It's like they're still living in 1930.
  • For charges so serious, it doesn't make much sense to me. It's a test that in nature seems like it is just made for a quick rough assessment that is fast and easy to do in the field. Great for weeding out who is worth the time to take to the station for a real test.
    • It isn't! At least in Netherlands where I live they do a blood test at the police station if the breathalyzer shows too much alcohol.
  • OK, I get it, the user interface etc. should be computerized for convenience.

    But the part that "holds up in court" should be as close to the raw data as possible, which can and probably should be analog or at the very least a very simple, relatively-easy-to-audit-for-correctness digital system.

    This web site [breathalyz...tester.com] describes a breathalyzer which appears to be analog. It also describes an intoxilyzer, which uses a microprocessor. If the electrical pulse being fed into the microprocessor can be captured for later p

    • by hey! ( 33014 ) on Thursday May 10, 2018 @12:02PM (#56588588) Homepage Journal

      The issue isn't with the software per se, but what the examination of the software revealed about the units as a system. If you used op amps instead of microcontrollers most of those issues would still be there.

      The sensors used are temperature sensitive. The configuration used by the police disabled ambient temperature checks, which I guess you could call a digital issue. The device lacks a breath temperature sensor, which means that people with warmer than average breath could get false positives.

      These devices also should be re-calibrated after a fixed number of uses; instead the state was re-calibrating them on a fixed schedule. While that schedule might work for an *average* device, devices that had been heavily could b e giving spurious readings.

      On the flip side the device uses two different types of sensors to measure alcohol, and rejects readings where the sensors give different answers. This might mitigate some of the defects in how the state used them, but nobody can be sure. All we have is the assurance of the state authorities that the devices "have been tested to meet our business needs," without any specifics about what the test entailed.

      The danger of these things is that they give you a number and it all seems so scientific and precise. You don't get the hemming and hawing that comes with a human opinion, metadata that helps you decide how certain you should be of that opinion. Layman don't understand the limitations of technology, they assume the tech should "just work". I'd trust a sophomore engineering student to devise policy for using these things over a police chief with decades of law enforcement experience.

  • All about the $$$ (Score:5, Interesting)

    by Zorro ( 15797 ) on Thursday May 10, 2018 @11:35AM (#56588336)

    A Drunk Driving conviction is big business in California.

    Of course they would tweak the test to get more and more money.

    You can easily spend $15K if you get one.

    • California has an implied consent law which requires those arrested on suspicion of drunk driving to submit to chemical testing to establish BAC. Breathalyzers are generally used to establish cause for arrest. So while the test being inaccurate may throw out a lot of "potential reasoning" for arresting a person, there could be a multitude of other factors. Factors like smelling alcohol on the breath, improper driving, inability to pass a sobriety test, and certain medical indicators (non-responding eye dila
  • by PPH ( 736903 ) on Thursday May 10, 2018 @11:37AM (#56588364)

    The neurological deficits of drinking (and using many other drugs) persist long after blood levels have dropped to zero. So either develop tests that measure actual impairment (and bust a lot more people) or just admit that so many people are impaired but sliding under the limits that we may as well just let them drive.

    • If we did that we would solve the transportation crisis in one jiffy. Virtually nobody will be able to drive.

      Fortunately, those autonomous cars will be cruising down the pike Real Soon Now and all will be good. That and Amazon 30 minute delivery, virtual reality goggles, Brwando and 'bating.

      • by PPH ( 736903 )

        Virtually nobody will be able to drive.

        That suits me. We are a long way past the point at which we should have been culling bad drivers and using them to create a demand for public transit.

    • WTF?

      Bullshit. They've gone way past testing for impairment. They're pushing for 0.05 now...the 'medical definition' of drunk is 0.15. Yes I realize the AMA eventually rolled over, but they made their point first. Your judgement goes to _shit_ at about 0.15, up till there, slower reactions.

      If 0.05 is, by definition, unable to drive, then 70 years old is, by definition, unable to drive.

      And yes, if you're massively hungover, odds are you are still 0.10. Monday morning is actually a fairly big time for D

    • by CHK6 ( 583097 ) on Thursday May 10, 2018 @01:17PM (#56589230)
      The officer needs a simple mobile app that presents a series of pictures of the suspect asking them "who is pretty." Based on the calculated values of swiping right and left and the speed of the selections, should give a good enough reference point to start from.
    • The neurological deficits of drinking (and using many other drugs) persist long after blood levels have dropped to zero.

      Citation please.

  • Trust But Verify (Score:5, Insightful)

    by crow ( 16139 ) on Thursday May 10, 2018 @11:46AM (#56588438) Homepage Journal

    So in most cases they use the breathalyzer along with a field sobriety test to determine if they should arrest a driver, after which they normally draw a blood sample for a more precise test. (In most states, drivers can refuse the tests and receive an automatic license suspension, though that's often not as bad as a conviction, but it doesn't preclude a conviction based on the sobriety test alone.)

    So we have lots of cases where there is both breathalyzer test data and blood test data. This gives a huge amount of data that can be correlated. Also, the times of the test should be recorded, so expected declines due to delays between the two tests can be computed. So all we need to do is gather up the data from a few years of use, and then we can see what the reliability of the breathalyzer is in comparison to the blood test.

    We know that any test can fail (equipment failure, cross contamination, operator error, etc.), but this will give solid data on the expected error.

  • by Anonymous Coward

    Having worked at Draeger I am somewhat biased but I will also be able to provide a more in-depth description of the company itself. The company manufactures loads of equipment for diving (tanks, breathing apparatus), fire prevention, fire detection, infra-red cameras, alarm systems and more. Everything is obviously thoroughly documented, tested and accounted for due to risk of life. The R&D floor at the office I worked housed proper chemical and electronics labs containing millions of dollars worth of i

    • Lets be real, police officers are not fond of paperwork and they will only test you if they have good reason

      Catching a sufficient number of violators is one way for them to ensure promotions. Which kinda makes sense... after all if Officer X caught 100 bad guys and Officer Y caught 2, it does make Officer X look better at his job (all other things being equal.)

      There are also rumors of quotas.

  • by Impy the Impiuos Imp ( 442658 ) on Thursday May 10, 2018 @12:01PM (#56588576) Journal

    In building a breathalizer to detect wayyyyy too much drinking, one would think the first thing they did was extensively test the happy path.

    • by Ken_g6 ( 775014 )

      Wait, I'm confused. Is the happy path the one that involves "happy hour"? Or is the happy path the one that involves not getting a DUI?

    • One of my friends worked for a company which calibrated the units for the local police. He brought some home and we pulled it out at a party. Naturally this turned into a competition with a few people blowing 0.15 and up.

      Well these things have an audit trail in them which raised some eyebrows when the police printed it off when it was returned.

      • then there was the frat house that THE BUILDING blew "legally drunk" (there was so much in the air that the units registered "drunk" from the ac blowing)

  • Jeez, this diverges into rantings about various DUI laws when IMHO the real issue is "Can we prove it's accurate without looking at the source?". IMHO, yeah. You specify the list of requirements, neither knowing nor caring how the magic box does it's magic, and if it passes the tests it's good to go.

    If you have half a brain you automate these tests and retest the things every once in a while, like maybe while your taking the blood/urine sample and booking your suspect into jail.

    And yes, I've written
  • From the article, the findings from the defense experts were scenarios that could result in false positives. But, what's the false positive rate as a function of the reading? That's what's important. Readings are just samples that estimate the true characteristic. The experts found that readings near the legal threshold could be inaccurate. However, that should have been obvious even without examining the system. The real question is what the confidence levels as the readings get near the legal thresh

  • by Jason1729 ( 561790 ) on Thursday May 10, 2018 @03:54PM (#56590602)
    The Alcotest is a roadside screening device. People who fail the road side test are then taken to a station (or mobile truck during RIDE type programs) for a more precise test.

    The roadside screening only has to give the police officer reasonable and probable grounds to arrest the person and continue with the investigation and subsequent test. Even if this result proved 100% that the Alcotest produces a lot of false positives, it casts zero doubt on any convictions or even matters currently going through the courts. The cops would have had RPG on a good-faith basis and every right to have proceeded.

    Going forward, it may be possible to argue that with the alcotest proven unreliable it can no longer be used to establish RPG, but even that won't be automatic because the roadside screening device isn't really required if the cop can say their were sufficient signs of impairment to arrest on impaired driving rather than over 80. The over 80 can then be laid at the station if the person blows over.

    TL;DR nothing to see here.
  • by MooseTick ( 895855 ) on Thursday May 10, 2018 @05:21PM (#56591050) Homepage

    Yet another thing self driving cars will fix. Once those are standard, there will be no more DUIs. There will also be no more tickets for speeding, running red lights, failure to maintain control, reckless driving, or any other moving violations.

    Sadly, I think cops will hate this. They want to be able to have a reason to pull someone over, especially if they are black (and this is coming from a white male who reeks white privilege). They will also fear this will eliminate a need for a major part of their job. I don't know the number, but suspect a sizable percentage of police activity involves traffic enforcement. If cars are driving themselves, their need will greatly diminish. At some point, municipalities will decide they don't need to pay someone to enforce laws that aren't being broken and there is no longer a threat to society by drunk and reckless drivers. I'm not sure what the final outcome will be, but it doesn't look good for the men in blue.

Things equal to nothing else are equal to each other.

Working...