Forensic science

This Chronicle of Sloppy Alcohol Breath Testing Highlights the Hidden Problems With Supposedly Scientific Forensic Evidence

Even when a technology is valid in theory, haphazard methods can lead to wrongful convictions.


In principle, machines that analyze drivers' breath can accurately measure the concentration of alcohol in their blood. But as The New York Times shows in an eye-opening exposé, that depends on using properly maintained and calibrated machines running error-free software. When police neglect those factors, innocent people can be convicted of driving under the influence. "Judges in Massachusetts and New Jersey have thrown out more than 30,000 breath tests in the past 12 months alone, largely because of human errors and lax governmental oversight," the Times reports. "Across the country, thousands of other tests also have been invalidated in recent years."

Here are some striking examples of faulty breath-test evidence used in DUI cases, as described by the Times:

  • Massachusetts, which in recent years has been plagued by fraud at the state's forensic laboratory, used Alcotest 9510 machines that are supposed to generate error messages when two methods of testing blood alcohol concentration arrive at contradictory results. "Instead," the Times says, "the devices printed a result"—a problem that the machine's manufacturer, Dräger, attributed to a programming error it says has been corrected. In addition, the crime lab "lacked a written procedure to set up and test machines," and "the lab had hidden records of hundreds of failed calibrations." Those problems eventually led to court orders throwing out more than 36,000 test results and prohibiting the state from using breath machines until the program has been reformed and accredited.
  • In 2010, Ilmar Paegle, the new head of the Washington, D.C., breath testing program, discovered that the District's Intoxilyzer machines were "generating results that were 20 percent to 40 percent too high." Paegle reported that his predecessor, Kelvin King, who was in charge of the program for 14 years, "had routinely entered incorrect data that miscalibrated the machines." The program also had been using test chemicals "so old that they had lost their potency." The city has notified defendants about the miscalibration issue in just 350 DUI cases spanning 18 months, but more than 700 other DUI defendants pleaded guilty during that period based on the assumption that their breath test results would lead to convictions.
  • Washington state replaced its old breath testing equipment in 2009 with Dräger's Alcotest 9510, even though the company said the machines were "not yet ready for implementation." A state toxicologist recommended that "we throw caution to the wind and proceed without paying up front for an independent evaluation." In 2015, consultants hired by a defense attorney concluded that the Alcotest 9510 was "not a sophisticated scientific measurement instrument" and "does not adhere to even basic standards of measurement." The problems included programming that could yield results rounded up to cross the 0.08 percent DUI threshold and the state's decision to forgo a sensor that measures breath temperature, which can skew test results.
  • When Colorado bought 160 new Intoxilyzer 9000 machines from CMI in 2013, it was in a hurry to get them up and running. A state lab technician later testified that "records were faked to show that he had calibrated dozens of instruments that he had never touched." The lab also "summoned assistants, including an intern, a CMI lawyer and a sales manager, to help." The 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," and "the lab kept using her signature after she left for another job." A judge in one case concluded that the lab had decided to "consciously disregard truth and accuracy." Defense lawyers in dozens of other cases are now challenging the test results used to convict their clients.
  • In New Jersey, the Times reports, "more than 13,000 people were found guilty based on breath tests from machines that hadn't been properly set up." In 2007 the New Jersey Supreme Court let defense attorneys hire experts who found "thousands of programming errors" in the software for Dräger's Alcotest 7110. "Dräger said it quickly fixed the problems," the Times says, "but the state never rolled out the software update."
  • Several states, including Florida, Ohio, Oregon, and Mississippi, are using a machine, the Intoxilyzer 8000, that Vermont deemed "unsatisfactory" in 2005, noting that it generated inaccurate results in "almost every test."

In addition to highlighting the potential for hidden problems (including fraud) with forensic evidence presented as scientifically infallible, the experience with alcohol breath testing is a cautionary tale for legislators, police, and prosecutors as they decide how to deal with marijuana-impaired driving. With alcohol, there is a firm scientific basis both for measuring blood levels with breath tests and for correlating them with impairment. Neither is true for THC. The best that breath, saliva, or even blood tests can do is confirm that a driver has consumed cannabis. They cannot show whether he was impaired by cannabis while he was driving.

In cases where there is independent evidence of impairment, a positive result for THC can suggest the cause. Even when tests are used for that limited purpose, and even when the technology has been validated, it is not safe to assume results are accurate in practice.

You might think that police and prosecutors have a strong incentive to make sure the evidence on which they rely can withstand scrutiny, given the consequences once sloppy methods are exposed. But that incentive is often overridden by short-term expediency, as demonstrated by the continued use of notoriously unreliable drug field tests. This chronicle of laziness, incompetence, and outright fraud in alcohol breath testing underlines that point.

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  1. In New Jersey, the Times reports, “more than 13,000 people were found guilty based on breath tests from machines that hadn’t been properly set up.”

    It’s Jersey. You’re better off in a cage.

    1. double-pay for being required to test the breath of people from New Jersey.

      1. Not to mention all the Quebecuoi tourists on the boardwalk.

  2. One obviously unpalatable solution is to skip the predictive nature of these “crimes” and base crime on actual harm. Nail those who cause accidents instead of all this hocus-pocus over those who might cause harm.

    Or if that’s too straightforward, base cases on videos of dangerous driving and failed field-“sobriety” tests. I don’t give a crap whether someone’s drunk or stoned or sleepy or old or suffers from MS; I do care that they meet minimum standards, such as reaction time, vision, and alertness.

    1. Beat me to it (see below). I agree.

    2. Field sobriety tests penalize folks with neurologically-related balance problems, which may have zero impact on anything they do while sitting down.

      1. Perhaps you missed the implication that these field-“sobriety” tests should actually be related to testing what matters to be a safe driver. Nowhere did I endorse existing protocols.

        It should be obvious and unsaid that every law should be on-point.

      2. Field sobriety tests penalize folks with neurologically-related balance problems, which may have zero impact on anything they do while sitting down.

        Prove it. Find me the neurologically unbalanced individual that’s driving a car and was mistakenly arrested after failing *only* a field sobriety test. Sullum, of whatever journalistic quality he may be, just showed us more than 40,000 tests and 13,000 convictions. Show us one person who’s been wrongfully convicted for failing a field sobriety test because of a neurological condition.

        1. Well I can’t say mine was a neurological condition unless lack of grace is a neurological condition (I have been compared to a bull in a china shop all my life). I did fail the field test (2 of 3, passed my ABC’s) only to blow a .02. I was still arrested for a DUI due to being underage (19 or 20). I wasn’t convicted though of DUI, just had to plead to the lesser charge of underage possession.

        2. I’d say a DUI arrest is bad enough even without a conviction. And people definitely get arrested simply for failing the field sobriety tests.

          1. And people definitely get arrested simply for failing the field sobriety tests.

            Legitimately even.

            It’s a non-sequitur. The police can’t know who has a neurological condition and will fail a FST a priori. Their best bet is to pull someone over who’s driving erratically. At which point, it’s moot whether their neurological condition renders them unable to pass the FST or not. If they had their neurological condition (as well as all other conditions) under adequate control, they wouldn’t have been driving erratically. He’s posited a faux perfect non-solution as an argument against a perfectly acceptable and broadly applicable solution, not just letting hard cases make bad law but actively using them to preserve existing worse law.

            If these sweeps were so frequent and people matching the description being caught up in them with any frequency we shouldn’t have much trouble finding someone. So far, we’ve got one person (myself) who has repeatedly suffered and been treated for BPPV (a condition very much analogous to the one described) but never been pulled over for driving erratically or arrested for failing a FST, one person who’s failed a FST but hasn’t got a medical condition and was otherwise impaired and 1-2 other people asserting that it does happen.

            1. one person who’s failed a FST but hasn’t got a medical condition and was otherwise impaired

              If that person is me, I certainly wasn’t impaired (.02 < .08). Otherwise carry on because I agree that the state should be forced to show that your driving was erratic before any such test could be administered or used as evidence against you.

              1. I certainly wasn’t impaired (.02 < .08)

                So the cop pulled you over knowing you were a bull in a china shop and would blow a .02?

                P.S. .02 < .08 does not mean (not) impaired.

              2. .02 < .08 does not mean (not) impaired.

                To mine and Á àß äẞç ãþÇđ âÞ¢Đæ ǎB€Ðëf ảhf’s and, a degree, your own point.

                For some people 0.08 isn’t going to be an impairment, for others who are just clumsy, careless, underage, or suffering from a neurological condition, 0.02 is well into impaired territory whether the driver thinks they are or not.

            2. And if police were only giving sobriety tests to people who were driving erratically, that would all make a lot of sense. But you know well that if a cop wants to fuck with you, he will. Stop you for a tail light out (whether or not it’s actually true), haul you out of the car and make you dance for your freedom.
              The fact that it can happen is enough for me. I don’t trust cops’ discretion.
              And if you decline to let them search your bodily fluids without a warrant, you probably lose your license for a while.

              1. The fact that it can happen is enough for me. I don’t trust cops’ discretion.

                It already happens whether you trust it or not. I don’t know who you are, but the real Zeb isn’t/wasn’t this slow.

      3. Field sobriety tests penalize folks with neurologically-related balance problems, which may have zero impact on anything they do while sitting down.

        I won’t take this accusation sitting down.

  3. To achieve forthright reporting, the Massachusetts part of this story has to acknowledge that the state forensic lab was criminally corrupted on a far wider scale than just breathalyzer tests. Many thousands of drug convictions have also been overturned.

    1. Their “M” should be revoked. From now on it’s Assachusetts.

    2. Yeah, I keep getting calls from headhunters trying to persuade me to come work for the State Police crime lab that’s just over the border from me. I keep telling them there’s no way in hell I’m gonna work for Massachusetts in any capacity.

  4. O/T – Heeeere HihnHihnHihnHihnHihn…

    On Island that Banned Guns, Prosecutor is Shot Dead

    1. The men had been plotting the killing for over a month, according to local law enforcement officials, who are collaborating with the FBI.

      *rubs temples as words like ‘deep state’, ‘open borders’, and ‘globalism’ pop into his head*

      I can only assume the FBI would be just as on top of things if she’d been shot to death in Wisconsin.

    2. Well, guns are not quite banned:

      The grisly incident has rattled the community of 12,000 people, where crime rates are low and only police can carry guns.

      Obviously the suspects are police officers and the article just failed to mention that because it’s obvious.

      1. Nope, it absolutely couldn’t have been the cops.

        According to the article she was shot while out walking her dog, and there is no mention that the dog was shot. The cops would have shot the dog first.

      2. It starts off with this wonderful community. No guns. Crime rates are low.

        But then, she was trying to help the majority of people have laws on the books… well, if there are no laws, it’s difficult to have high crime rates, isn’t it?

        Then it goes on to talk about the horrible sex trafficking that she deals with. And she was so scared she slept with a machete. And one of the suspects arrested for shooting her is a cop who used to work with her. Sounds like a great little gun-free paradise.

    3. She was trying to help the majority of the community have laws in the books,” he said, and “there may be that part of the community that was not so happy

      Obviously murdered by your libertarian cousins.

  5. I’ve never understood the rationale for using BAC as a measure of impairment, or why they continue to search for a similar measurable limit for marijuana, other than cases of the driver being unconscious or otherwise incapacitated. Why not just stick to a sobriety test measuring reaction time? I don’t care if the person has been drinking or smoking too much, or if they’re just too old to drive – if they caused an accident or are all over the road, regardless of the cause of the impairment, then they are a danger to others and shouldn’t be driving. Just find a better way to measure impairment rather than a one size fits all blood content measurement.

    The downside to this approach is that it’s open to interpretation and some asshole cops will use it as a punitive action. But I tend to think they do that already.

    1. As someone who failed the walking straight line and hold one leg up for 30 seconds part of the field test and then blew a .02, I’m glad they have the BAC. Still was charged with DUI but that was do to my age and it was dropped by the prosecutor.

    2. Because the alternative is to require cops to have judgement.

      All laws like that are just to help lazy prosecutors and incompetent cops. Impairment should be based on observed events, not an arbitrarily selected number from a damn computer.
      Demand a jury. Ask these questions: does that machine contain any components that are directed by programming? Have the manufactures procedures and maintenance been followed without fail? (regardless of the answers) Gentlemen of the jury, I submit to you that there is ample room here for reasonable doubt. Have any of you managed to live your life so far without encountering a “computer error”?

      1. See my last comment.

        There are plenty of ways to make it an objective test of reaction time and coordination without it being a judgement call. Create a video game test where the person has to be able to press a button when they see a color change, or some other measure of cognition, and record the entire thing for use in court (this is just off the top of my head). There are a thousand ways to skin that cat without a subjective test of having someone walk a line or recite the alphabet backwards, or using an arbitrary measure of chemical in the bloodstream that has varying effects across individuals.

    3. I agree with your comment but I don’t agree with you’re “reaction time” statement because, like you said, it’s open to interpretation. I’ve been saying the exact thing you said for as long as I can remember. The hell with DUI laws and fuck the never ending drug war!

      1. “and fuck the never ending drug war!”

        1. Hasn’t anyone ever told you to never stick your dick in crazy?

        2. You don’t fuck the drug war, the drug war fucks you.

  6. Not that any of us ever expect to need it, but in the event you’re pulled over under suspicion of DUI, will police take you to the station and do a blood draw if you politely refuse the brethalyzer?

    1. Depends on the jurisdiction. In some states, that’s the protocol. In others, merely refusing the breathalyzer is all the “evidence” they need.

      1. How can refusal be taken as evidence if you’re voluntarily offering other means of testing your BAC?

    2. In Texas it is up to the arresting officer as to which method is used, and refusal typically results in loss of license. However, you are entitled to an independent blood draw and lab test, at your expense, that must be within two hours of the one the police give you. Not sure how you will get that in jail, but it is supposed to be an option.

  7. What kind of sick twisted person is willing to go along knowing the results are bad?

    1. The Colorado one baffles me. I could kinda understand that they may’ve been using someone’s digital signature without their knowledge/permission, but unless the technicians were getting pay raises to do so (in which case they should be charged) I can’t understand why you wouldn’t just say you’ll go find work someplace that won’t ask you to commit felonies and see if any journalists would be interested in the story in the meantime.

    2. Kamala Harris

  8. “You might think that police and prosecutors have a strong incentive to make sure the evidence on which they rely can withstand scrutiny, given the consequences once sloppy methods are exposed.”

    This is too kind. The police have a vested interest in being able to arrest lots and lots of people–felonies, much preferred, of course, and preferably those likely to be committed by non-threatening people. Very often, the “consequences” won’t occur because the sloppy methods won’t be exposed. And even if they are, most of the people with an interest in keeping the high crime machine aren’t going to suffer. A cop who neglected to keep his breathalyzer functional isn’t going to be punished. Neither is the DA who relied on the evidence, nor the judge whose conviction is overturned. And, no, I’ve never been busted, much less convicted, on a booze charge, or any other.

  9. Blood testing for a blood level is of course the gold standard. It should leave a second sample for follow up/confirmatory testing.
    Testing to deprive one of their liberty should at least be as robust as that to see if one can participate in sports.

  10. I designed a new field test for the police.
    The person being questioned presses a button and if the light turns red they are guilty.
    The design consists of a box a red Led (other colors not needed) a battery and a push button.
    I will sell it for $500 a peice.

    OH and something something clingers something

  11. “…given the consequences once sloppy methods are exposed.”

    Officer Wimpy states he will gladly pay Tuesday for his own corrupt-career-enhancing-false charge today.

    ” The city has notified defendants about the miscalibration issue in just 350 DUI cases spanning 18 months, but more than 700 other DUI defendants pleaded guilty during that period based on the assumption that their breath test results would lead to convictions.”

    Civil servant “bean counters” would declare that a clear win… for guberment coffers and retirement plans. And no official apologies given because it was all about public safety and what hero would be expected to do that. As a realist, actual accountability will not factor in.

  12. Intoxilyzer 9000

    That was my nickname when I was a bartender.

    1. I don’t remember you.

  13. “In 2010, Ilmar Paegle, the new head of the Washington, D.C., breath testing program, discovered that the District’s Intoxilyzer machines were “generating results that were 20 percent to 40 percent too high.”

    Yeah, cannot have your elected betters in DC getting unnecessarily caught up in bad faith DUI charges. Trickle down Justice reforms start at the top.

    And you can tell who is at the top by their treatment. “Rhode Island congressman Patrick Kennedy involved in car accident near U.S. Capitol…Today, Kennedy said, “Apparently, I was disoriented from the medication” and that he “never asked for any preferential treatment.” He also announced that he is checking himself into the Mayo Clinic in Rochester, Minnesota. It is not known whether any sobriety test or arrest was made. Kennedy was not injured.

    ” Kennedy drove his car into a security barrier near the Capitol building. When questioned by the police, he told them that he was “headed to the Capitol to make a vote,” when no votes were scheduled for that time of the morning.

    FFS- No sobriety test?! This is a highly suspect Hyannis Port Kennedy, and Teddy’s son no less. Apparently, Kennedy did not even have to invoke his white (democrat) privilege (Do you know who I am?) as its presence was sufficiently detected upon identification.

  14. when two methods of testing blood alcohol concentration arrive[d] at contradictory results[,] “the devices printed a result”—a problem that the machine’s manufacturer, Dräger, attributed to a programming error

    Right. Let the lawsuits begin.

  15. Studies show that these breathalyzers have a 50% margin of error.
    There is MUCH more to the draconian laws,propaganda and bogus stats that are force fed to us. Example: M.A.DD gets their stats for alcohol related accidents from the NHSTA. But what NO ONE knows,although it’s easy enough to find is,that the NHSTA BAC threshold is .001 for alcohol related incidents. NOT accidents. Yet, M.A.D.D uses these stats from the NHSTA to feed us propaganda about drunk driving. The actual number of drunk drivers is about 4% (BAC .08) of the NHSTA. If you want the real stats and how this is all a scam,money grab. Check out the web site “” A real eye opener! And should scare the hell out of you!

    1. The other problem is that if one of the drivers in an accident was drinking, then the accident is “alcohol related,” regardless of culpability. When I was in college, I was walking to a party and witnessed a car blow through a red light and hit another car that had been driving perfectly okay. The driver who ran the red light hadn’t been drinking, but the actual victim had been. Guess who ended up getting cuffed and stuffed. That accident was surely classified as alcohol related, despite the fact that alcohol did not contribute to the accident in any way. Also, when you get into a discussion with any anti-alcohol crusaders about .08 vs. .1, you will get an obvious pantload of manipulated and misrepresented statistics thrown your way. Screw MADD. Screw ’em good and hard.

  16. Of course, now that dash mounted cameras are cheap, we could side-step a lot of this aggravation by only having officers write tickets for observed dangerous driving.

    And as an added bonus, such a policy could cause MADD to suffer a collective aneurysm.

    1. The state police in Massachusetts don’t use them. I think it’s because the general citizenry are so statist that they are naively accepting of the word of state “authorities” without question. Why mess that up by tainting criminal proceedings with objective evidence. Note BTW that this is one of the wealthiest police departments per officer in the country, perhaps the wealthiest. Screw the MA state police. Screw ’em good and hard.

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