Roadside Breath Tests Are Just As Unreliable As Field Drug Tests

from the magic-8-ball-says... dept

Portable alcohol testing equipment (a.k.a. breathalyzers) have been called "magic black boxes" and "extremely questionable" by judges. And yet, they're still used almost everywhere by almost every law enforcement agency. They're shiny and sleek and have knobs and buttons and digital readouts, so they're not as immediately sketchy as the $2 drug-testing labs cops use to turn donut crumbs into methamphetamines. But they're almost as unreliable as field drug tests.

Even when the equipment works right, it can still be wrong. But it so very rarely works right. Cops buy the equipment, then do almost nothing in terms of periodic testing or maintenance. A new report from the New York Times shows this equipment should probably never be trusted to deliver proof of someone's intoxication. And the failure begins with the agencies using them.

The machines are sensitive scientific instruments, and in many cases they haven’t been properly calibrated, yielding results that were at times 40 percent too high. Maintaining machines is up to police departments that sometimes have shoddy standards and lack expertise. In some cities, lab officials have used stale or home-brewed chemical solutions that warped results. In Massachusetts, officers used a machine with rats nesting inside.

There are also problems with the machines themselves, even when they've been properly maintained. And the problems aren't limited to single manufacturer. Dräger, the company that owns the name "Breathalyzer," produced a machine that experts said with "littered with thousands of programming errors." This finding was made during a rare examination of breath-testing equipment by defense attorneys granted by the New Jersey Supreme Court. Those findings resulted in zero lost law enforcement customers for Dräger.

CMI's breath tester fared no better when examined by toxicology lab experts. CMI's Intoxilyzer gave inaccurate results on "almost every test," according to the report. This didn't stop multiple law enforcement agencies from purchasing CMI's tech, even when a Florida court had this to say about the Intoxilyzer.

The Intoxilyzer 8000 is a magic black box assisting the prosecution in convicting citizens of DUI. A defendant is required to blow into the box. The defense has shown significant and continued anomalies in the operation of the Intoxilyzer 8000’s operation. The prosecution argues most of the tests do not show anomalies. In fact, a high percentage of the tests may show no anomalous operation. That the Intoxilyzer 8000 mostly works is an insufficient response when a citizen’s liberty is at risk.

In the state of Washington, state police spent $1 million on Dräger breath testers to replace aging machines. Rather than roll this out in a controlled fashion with proper testing, state officials opted to bypass outside testing of the software to speed up deployment to police officers. Six years after this speedy rollout, the device's reliability was called into question in court. The court allowed defense lawyers to review the software. The result of this testing was never made public… at least not officially. The experts who reviewed Dräger's equipment had this to say about it:

The report said the Alcotest 9510 was “not a sophisticated scientific measurement instrument” and “does not adhere to even basic standards of measurement.” It described a calculation error that Mr. Walker and Mr. Momot believed could round up some results. And it found that certain safeguards had been disabled.

Among them: Washington’s machines weren’t measuring drivers’ breath temperatures. Breath samples that are above 93.2 degrees — as most are — can trigger inaccurately high results.

Dräger sent the researchers a cease-and-desist order, forbidding them from discussing their findings with anyone and demanding they destroy all copies of their report. Unfortunately for the company, the preliminary report had already been distributed to other defense lawyers and made its way to a number of websites.

The rush to deploy equipment wasn't just a problem in Washington. The same thing happened in Colorado, but the rollout was even more haphazard and borderline illegal. There weren't enough techs available to set up the purchased equipment, so the manufacturer (CMI) sent a salesperson and one of its lawyers to help with the initial calibration and certification. Only one actual lab supervisor was involved. The rest of the workforce was composed of assistants and interns. At best, one person was qualified to do this job. Since this seemed likely to pose a problem down the road if the equipment or readings were challenged in court, the state lab used an extremely-questionable workaround.

[T]he lab’s former science director said in a sworn affidavit that her digital signature had been used without her knowledge on documents certifying that the Intoxilyzers were reliable. The lab kept using her signature after she left for another job.

In Washington, DC, faulty equipment wasn't taken out of service by the person overseeing the program. Instead, the person meant to ensure the equipment was working properly was making everything worse when not acting as a freelance chemist.

Mr. Paegle’s predecessor, Kelvin King, who oversaw the program for 14 years, had routinely entered incorrect data that miscalibrated the machines, according to an affidavit by Mr. Paegle and a lawsuit brought by convicted drivers.

In addition, Mr. Paegle found, the chemicals the department was using to set up the machines were so old that they had lost their potency — and, in some cases, Mr. King had brewed his own chemical solutions. (Mr. King still works for the Metropolitan Police Department. A department spokeswoman said he was unavailable for comment.)

Once the courts were informed, 350 convictions were tossed. The damage here was relatively minimal. In Massachusetts -- where crime lab misconduct is an everyday occurrence -- 36,000 tests were ruled inadmissible. In New Jersey, 42,000 cases were affected by breath test equipment that had never been set up properly.

Very few corrective measures have been implemented by law enforcement agencies. The fixes that are being made have almost all been the result of court orders. The unreliability of roadside breath tests have led several courts to reject pleas or prosecutions based solely on tests performed by officers during traffic stops. But none of this seems to have had an effect on law enforcement agencies who continue to purchase unreliable equipment and deploy it with proper safeguards or testing.

Breathalyzers are field tests in more than one sense of the word. Drivers are merely lab rats who face the possibility of losing their freedom, their licenses, and possibly their vehicles because a "magic black box" told a cop the driver was under the influence.

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Filed Under: accuracy, breathalyzers, dui, evidence, police, roadside breath tests, testing

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  1. icon
    That One Guy (profile), 20 Nov 2019 @ 8:13pm

    The truth has nothing to fear from investigation

    Dräger sent the researchers a cease-and-desist order, forbidding them from discussing their findings with anyone and demanding they destroy all copies of their report.

    Because nothing says 'we stand behind our products' like demanding that researchers testing it's accuracy not say anything about it with anyone, and destroy all copies of the research into it.

    As for continued police use of 'questionable'(to put it very generously) breath testing devices I can't say I'm surprised. Much like 'drug dogs' the point far too often is to provide justification for what they've already decided is the case in order to secure guilty prosecutions/plea deals and make themselves look better as Doing Something. If the devices are incorrectly flagging people are too intoxicated to drive then that just means they can mark down yet another drunk driver on their stats, and if that means someone who wasn't in fact over the limit has to deal with fines/jail time then it's not like that will cost the cop anything, so no big deal.

    reply to this | link to this | view in thread ]

  2. identicon
    Anonymous Coward, 20 Nov 2019 @ 9:48pm

    Proud 7 time DUI survivor

    think of the children

    reply to this | link to this | view in thread ]

  3. icon
    Ngita (profile), 20 Nov 2019 @ 10:12pm

    Australia and NZ. An over the limit reading in the field simply mean a visit to the Station or Truck where another machine that is not roadside portable and presumably more accurate reading is run. It can occur that the additional time can lead to someone just over dropping to just under.

    But at least on TV you never see anyone dropping from 2-3 times over to under or read in the press that any complaints that they got off after a road side reading grossly over the limits.

    reply to this | link to this | view in thread ]

  4. identicon
    Anonymous Coward, 20 Nov 2019 @ 10:47pm

    Re: BAC teating

    And even then an option to request a blood test is available.

    The roadside tests are not evidenciary they are just indicative further investigation is required.

    reply to this | link to this | view in thread ]

  5. identicon
    Anonymous Coward, 20 Nov 2019 @ 10:49pm


    At my high school senior party, a tradition to find a farm far away from any normal law enforcement and throw a massive illegal kegger, the police busted it after about 7-10 hours of drinking and several kegs.

    Someone decided it was a good idea to drive home from it even through there were sober designated drivers prearranged for people.

    Anyway, the cops just tested people and wrote tickets. The people who were caught just had to pay the underage drinking tickets. There is absolutely no reason to believe the machines were accurate though because I blew an obviously wrong number.

    reply to this | link to this | view in thread ]

  6. identicon
    Anonymous Coward, 20 Nov 2019 @ 10:56pm

    Re: Re:

    That is from the USA

    reply to this | link to this | view in thread ]

  7. icon
    tweetiepooh (profile), 21 Nov 2019 @ 1:07am


    And in the UK you don't give a test within (20 mins I think) of drinking last drink and the road side test "fail" will lead to being taken to the police station for the evidential breath test. You give two samples and the lower figure is used.

    I also believe there is a margin over the legal limit you have to be over for action to be taken but rules are getting stricter and when you see the results of driving while incapacitated (drugs/drink/illness/tiredness/distraction) it's quite proper to keep roads safer.

    reply to this | link to this | view in thread ]

  8. identicon
    Patrick H, 21 Nov 2019 @ 1:55am

    I wonder what the response would be if it where found these machines were reading low, in the defendants favor.

    reply to this | link to this | view in thread ]

  9. identicon
    Anonymous Coward, 21 Nov 2019 @ 1:57am

    Re: Re:

    I blew a 0.0
    I wasn't even close to a 0.0

    reply to this | link to this | view in thread ]

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  11. icon
    That One Guy (profile), 21 Nov 2019 @ 4:17am


    They'd have been removed from use within the week, with a very stern letter sent to the seller about how vital it is for the machines to be 'accurate', and if they were going to give erroneous readings it would be much better if they were giving high readings, 'for public safety' of course.

    reply to this | link to this | view in thread ]

  12. identicon
    Anonymous Coward, 21 Nov 2019 @ 6:38am

    I had better test myself with the venerable Intoxilyzer 800 before stepping into my brand spankin new 6000 SUX


    reply to this | link to this | view in thread ]

  13. identicon
    Anonymous Coward, 21 Nov 2019 @ 7:31am


    In the US road side breath tests are used to establish probable cause for the arrest, and are not used in the criminal proceedings as evidence. The evidence in the court case is a blood or breath test performed after the arrest.

    reply to this | link to this | view in thread ]

  14. identicon
    kog999, 21 Nov 2019 @ 7:33am


    its true these tests are so unreliable, sometimes they even say that a person is not drunk. a much better way would be to use a dog. after all we know that dogs have a good sense of smell and so can be trained to smell alcohol.

    reply to this | link to this | view in thread ]

  15. icon
    Bergman (profile), 21 Nov 2019 @ 7:54am

    Re: Re:

    Whereas in Canada, they can test you up to two hours after you last operated a vehicle, and if you have alcohol in your system -- for example, going home after work, eating dinner 30 minutes after getting home and having a few beers 30 minutes after dinner -- you get a DUI.

    reply to this | link to this | view in thread ]

  16. icon
    Bergman (profile), 21 Nov 2019 @ 7:56am

    Re: Re:

    Yes, but they cannot compel the after-arrest test unless there has been an arrest, and they use the wildly inaccurate test to justify the arrest. That's an invasion of privacy, under US laws.

    And who is to say the second test is any more accurate than the first?

    reply to this | link to this | view in thread ]

  17. icon
    Bergman (profile), 21 Nov 2019 @ 7:58am

    Something even more ridiculous than alcohol breathalyzers

    There's a new type of breathalyzer out there, that detects cannabis metabolites. Those metabolites can trigger a positive result on the thing, up to 28 days after the intoxication effect wears off.

    They can't detect actual cannabis intoxication, mind you, just whether someone ingested some in the past month. But a positive result on them is treated by police as proof of DUI.

    reply to this | link to this | view in thread ]

  18. identicon
    Paul B, 21 Nov 2019 @ 8:05am

    Re: Re: BAC teating

    Often the laws give you the DUI punishment for a failed breath test as a civil punishment. They also give you the punishment for refusal of the test.

    MADD went a bit crazy on DUI laws over the last 20-40 years. Making it very hard to challenge breathalyzers, allowing much lower than normal evidentiary standards for the black box testing machines, and often making punishments automatic and civil for both refusal to test and for any failed test (even if later found out to be incorrect via blood etc.).

    reply to this | link to this | view in thread ]

  19. identicon
    Anonymous Coward, 21 Nov 2019 @ 8:26am

    Re: Something even more ridiculous than alcohol breathalyzers

    With the legalization of hemp and CBD products, it will undoubtedly get tossed out fairly soon in the courts.

    reply to this | link to this | view in thread ]

  20. identicon
    Anonymous Coward, 21 Nov 2019 @ 8:52am

    Cops should have to blow before public

    If these machines are so 'reliable' the cop who is administering the test should have to blow in the machine before the person they want to test...

    If the machine says the cop is drunk, then the citizen gets to perform a citizen's arrest and throw the cop in the back of his own cruiser until backup arrives.

    If the machine says the cop isn't drunk, then obviously the machine is unreliable and can't be used to test the public...

    reply to this | link to this | view in thread ]

  21. identicon
    Anonymous Coward, 21 Nov 2019 @ 10:07am

    Re: dogs


    reply to this | link to this | view in thread ]

  22. identicon
    Anonymous Coward, 21 Nov 2019 @ 11:16am

    I dont know why they need a machine to tell them someone is a crook, some leos receive special training that enables them to spot a drugged and/or drunk individual via sight ... or so they claim. Why do they need a yes-machine to agree with their predetermined conclusions?

    reply to this | link to this | view in thread ]

  23. identicon
    Canuck, 21 Nov 2019 @ 11:44am

    Re: Re: dogs

    You have to ask?

    reply to this | link to this | view in thread ]

  24. identicon
    Jordan Chandler, 21 Nov 2019 @ 12:02pm

    learned lesson

    This article teaches me virtually anyone who can afford to hire a competent lawyer will get off on any DUI charge.

    reply to this | link to this | view in thread ]

  25. identicon
    Anonymous Coward, 21 Nov 2019 @ 12:15pm

    I very much doubt that the things are accurate, because of intrinsic problems with the measurement method and the conditions under which it's done.

    But let's not go crazy here. You could just about teach an ape to calibrate an instrument like that. There's no reason a lab intern shouldn't be able to do it. Maybe not a LAWYER, mind you, but anybody with a little bit of clue about instruments and measurement in general, and at most a few hours of training, should be fine to do the calibratrion.

    Same goes for "homebrew" calibration solutions. They're not going to be using anything that exotic or hard to mix up properly.

    If the things are miscalibrated or uncalibrated, it's because it's not being done on schedule at all, or because the people doing it don't give a fuck. Which is far worse than being unqualified.

    reply to this | link to this | view in thread ]

  26. identicon
    Anonymous Coward, 21 Nov 2019 @ 12:18pm

    Re: learned lesson


    Usually the judge doesn't care about the bad science. The science is how we know we executed innocent people after the fact yet some places still refuse to test DNA evidence about the people on death row.

    reply to this | link to this | view in thread ]

  27. icon
    Uriel-238 (profile), 21 Nov 2019 @ 12:30pm

    Failing breathylizers

    This is what the helium balloons are for.

    reply to this | link to this | view in thread ]

  28. icon
    Uriel-238 (profile), 21 Nov 2019 @ 12:36pm

    Observe my complete lack of surprise.

    An ex-girlfriend of mine had a propensity for bad driving habits, including getting home on her own after an overly social event. I got her a personal breathalyzer for Christmas, which she took rather well.

    Presuming retail breathalyzers are more accurate (which I haven't confirmed) or at least come in more accurate brands, this might be a good reason to have one, in case police tests are set too sensitive and one needs a second opinion on hand. It may not beat the ride, but it might help beat the rap.

    That all said, this story does contribute to the whole private prisons / filling jails with warm bodies narrative that's been developing for... decades now.

    reply to this | link to this | view in thread ]

  29. icon
    R.H. (profile), 21 Nov 2019 @ 1:52pm


    I remember reading over a decade ago that the best way to avoid a DUI conviction (after being charged, of course) was to request the calibration and maintenance records of the device they used for the roadside test. Unfortunately, that means that this article doesn't surprise me.

    reply to this | link to this | view in thread ]

  30. identicon
    George Washington, 21 Nov 2019 @ 3:14pm

    And in other news:

    "Afte r False Drug Test, He Was in Solitary Confinement for 120 Days
    Hundreds of New York State prisoners were locked in cells, denied release or removed from programs when tests erroneously showed they had used narcotics, according to a lawsuit."

    Nice to learn that massive, probably criminal, incompetence is not limited to the western part of the United States.

    reply to this | link to this | view in thread ]

  31. identicon
    bobob, 21 Nov 2019 @ 10:53pm

    In Texas, all of this is pretty much irrelevant, aside from losing your license for 180 days for refusing to take either a breathalyzer or blood test (officer decides which).

    If a cop decides you are impaired, he/she needs nothing at all but his/her judgment that you are impaired to arrest you. If you are asked to take a breathalyzer and fail the test, you then have the right to request an independent blood test (at your expense) within two hours. (This seems like a rather short amount of time to get that done, but perhaps impeding your ability to do that could be a defense strtegy.)

    Basically, if you are stopped and "suspected" of driving while intoxicated, you are already screwed if you aren't intoxicated, breathalyzer or not, and just about anything can be used to justify a stop.

    To see how easy it is to get stopped (although in this case, I was driving through Missouri), I was driving along going the speed limit (with out of state plates) and got pulled over. Why was I stopped. I was told I "touched the line 3 times, even though the cop in the car was positioned in such a way that he could not have seen me except when I passed in front of him. (Long hair in Missouri seems to amount to probable cause.)

    He kept me there for about 45 minutes and only let me go after he got tire of me asking if he'd ever used his taser on anyone and how well it worked among other questions he got tired of answering. (Not twelve hours later I got pulled over in Ohio and got a warning ticket for doing 57 in a 55.)

    Based on my experiences being stopped on various occasions, I'd say whether or not a breathalyzer is working or not (or a radar unit, whatever), if a cop decides to stop you for some reason that he/she cannot use in court for probable cause, those instruments double as props with judge and jury cred. Disputing the accuracy of the instruments sort of misses the point.

    Yeah, I've gotten real tickets for speeding, but I never object to those. (I hate people who bitch about tickets they earned.) I've also been given passes when I was speeding, so as I see it, whatever happens when someone gets stopped depends more on what the cop wants to do than any supposedly impartial data churned out by an instrument.

    What really needs to be addressed is police accountability for every decision they make. Only then will the reliability of the instruments they use matter.

    reply to this | link to this | view in thread ]

  32. icon
    sj1020 (profile), 3 Dec 2019 @ 6:34pm

    Re: dogs

    Do you really think that would work? Or are you joking? Because I don’t even drink alcohol at all but I got a DUI for taking prescription meds the previous night & it was still in my system when I went to work the next morning and had an accident. No alcohol was found but I agreed to a blood test. But what you’re saying is that if a friend spilled beer or wine on me, I could get a DUI because the dogs smelled it on me.

    reply to this | link to this | view in thread ]

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