Police Blotter: Court won't release breathalyzer source code
Police Blotter is a regular CNET News report on the intersection of technology and the law.
What: A Minnesota man accused of drunk driving says he should be able to review the source code of the Intoxilyzer 5000EN breathalyzer used by police.
When: Minnesota Court of Appeals rules on January 13.
Outcome: Request for source code rejected.
What happened, according to court documents and other sources:
If police think you're driving while intoxicated, they'll probably demand that you blow into a tube connected to a simple portable computer. Your breath flows into a chamber with an infrared light and a sensor that's designed to detect alcohol vapor through a process called infrared spectrometry.
The problem is that the calculations depend on what assumptions the programmer made, including the relationship between your blood alcohol content and alcohol in your breath, which can vary with the individual. In addition, the programmer could have made coding errors along the way.
Which brings us to a question that has bedeviled dozens of judges for the last few years: Should a defendant have the right to review the source code--the step-by-step programming instructions--to a breathalyzer that police and prosecutors are using against him?
To computer scientists, there's little reason not to disclose the source code to a defense expert who can review the logic that the device employs; otherwise, it's a little like being convicted based on the word of an inscrutable black box. Defense attorneys have been zealously pressing that point in court. But prosecutors say it would be too disruptive and burdensome.
Nicholas Swendra is one of those DUI defendants asking prosecutors to hand over the source code to the Minnesota version of the Intoxilyzer 5000EN, made by a private company called CMI of Owensboro, Ky. The Intoxilyzer relies on technology that would have been state of the art in the early 1980s: a dot matrix fluorescent display, an RS-232 port, a Z80 microprocessor programmed in assembly language, and less than 100KB of RAM. CMI insists the source code is a trade secret.
The Minnesota government submitted an affidavit from a forensic scientist saying the source code was accurate, while Swendra's attorney countered by pointing out congressional testimony and a flurry of other court opinions authorizing a peek at the Intoxilyzer's instructions. (Defense counsel's goal is to get the Intoxilyzer evidence tossed out of court, or to persuade prosecutors to drop charges.)
A district judge denied Swendra's request for additional information about the Intoxilyzer, saying that turning over the source code would be unreasonably burdensome and that the defendant could offer only speculation to support his argument that the source code is relevant. On January 13, a Minnesota appeals court agreed.
This will not be the end of the overall issue. Swendra could appeal, and other cases have reached different conclusions. For example, a July 2007 ruling from the Minnesota Supreme Court in a case involving accused drunk driver Dale Underdahl--reported by Police Blotter at the time--allowed the defendant to review the source code. A Florida court said in 2005 that state police can't use electronic breathalyzers as courtroom evidence against drivers. And another Florida judge ruled last month that the results of breathalyzer tests in more than 100 drunk driving cases will not be allowed to be introduced as evidence during trials.
Excerpts from Minnesota Court of Appeals' ruling:
The results of the Intoxilyzer breath test are presumed reliable under Minnesota statute. Because appellant stipulated to the Intoxilyzer's reliable administration, he bore the burden of presenting the court with "some evidence beyond mere speculation that questions the trustworthiness of the Intoxilyzer report." See Kramer v. Comm'r of Pub. Safety, 706 N.W.2d 231, 236 (Minn.App.2005).
In (the 2008 case called) Underdahl II, this court held that a finding of relevancy respecting the source code "must be premised on a showing that an examination of the instrument's software would show defects in its operation or at least would be necessary to determine whether a defect exists." We found that the party seeking discovery in Underdahl II failed to show relevancy because he furnished no evidence that the code would reveal testing deficiencies or that any deficiencies would affect test results and no evidence that the driver, who is permitted by law to test the machine, was deprived of access to any information that might be revealed by the source code.
As in Underdahl II, appellant made inadequate showings in the district court on the relevancy of the source code. Appellant theorized that, "[w]ithout the source code, the Intoxilyzer 5000 is just a machine that does nothing. The source code itself is absolutely relevant and material to the question of whether the test record in this case is accurate and valid." The district court found appellant's evidence (testimony on voting machine source codes, a New Jersey source-code report, and trial court opinions) unhelpful and concluded that "[p]etitioner has provided only speculation that the information provided by the Intoxilyzer 5000EN is even at issue in this case.... In this case and on this record, [p]etitioner is not entitled to additional discovery."
The district court acted within the scope of its wide discretion in its relevancy decision. It follows that we have no occasion to reach appellant's remaining argument that the court erred in addressing respondent's alleged possession of the source code.
Declan McCullagh, CNET News' chief political correspondent, chronicles the intersection of politics and technology. He has covered politics, technology, and Washington, D.C., for more than a decade, which has turned him into an iconoclast and a skeptic of anyone who says, "We oughta have a new federal law against this." E-mail Declan. 
I will not tell anyone how it works, only that it does work and it's findings should be taken as 100% accurate.
If you wish, you may also ask my friends for their opinions on whether it's findings are accurate, and they will agree with me.
Oh, and Declan is full of it on this one. While there might not be any reason for a computer scientist to not reveal their source code (though sometimes getting source code is problematic) what applies in the academic world does not necessarily apply to the corporate world. Declan should think back to his own academic career and ask himself how much of it applies to what he's doing now.
By law you can't refuse the test. It would be interesting to try to calibrate the test you just took to verify it's accuracy by insisting that your attorney be present with an alternate breathalizer to test at the same time you take the first test. This way you truly could say that your refuted or confirmed the test with your own independent source.
Oh and if they won't let you see how it works so, I'd not call that well known. You would have a theory (speculation) that can't be proven (due to being denied a peak at how the code works). In other words pretty much hearsay.
I think Grifter02 has a point. A Defendant should be able to question or investigate the tool that was used to convict him. This includes having the Source Code for the device. I think the courts just don't understand technology. How it works and more importantly how it doesn't work. Granted the defendant could be going for a loophole to weasel out of drunk driving, but that not the point or the important question.
I am sure the vendor does do everything in it power to make sure the device works. Tested the device to death. However, corner cases or unforeseen scenarios are possible in this case. The source code could offer evidience of faulty behavior. Therefore the source code is revalent in this case.
Hint to anyone pulled over. NEVER EVER EVER BLOW IN THE MACHINE! Nothing good can come out of it. I "know someone" that was pulled over, wasn't close to drunk, had a PERFECT field sobriety test (tape was able to be viewed after) and blew over the limit. He was also pulled over for a non 'drunk driving' offence so it's not like he was pulled over for swerving around or running into stuff.
If you don't blow, they (court/jury) has to go off the tape of your FST so if you're really able to drive, and the tape shows your obviously not impaired in any way, then you'll be found innocent. However, if you do refuse to blow the cop (normally) has the right to take you to jail (isn't that nice...)
I'm guessing, in this case, that there was no blood test to compare to, or else the breathalyzer would not have been needed as evidence.
But, just to satisfy you, I will partner with 4 other companies around the country to develop their own model of "The Magic 8-Ball," and I will reveal, only to them, exactly how it works. Now you may compare the results of my machine to those of the other Magic 8-Balls. I assure you, they will all be the same.
Let's not forget the guy was driving and he had to be noticably intoxicated to have been pulled over and asked to submit to the breathalizer. I can't believe some of you are actually siding with the drunk driver on this. Pray you or someone you love never gets on the road with one.
We're defending his rights, not his actions.
Also, you make a lot of assumptions in your statement. Considering you have no knowledge of the situation in which the breathalyzer test was conducted nor the character of the man accused, you shouldn't jump to conclusions.
The key issue being deprived of a way to verify the accuracy of the math built into the code. The other issue is that this is a public trial, of a member of the public, hinged on propriatary black box programming that they can't see. If the code is closed, it shouldn't be used in court.
If the breathalyzer's results are relevant to a possible conviction, then its sure as hell is relevant for one to be able to see how it got the kind of results it did. "unreasonably burdensome"? As if the proper application of justice was burdensome.
Such a release would allow this whole process to head towards resolution rather than continue to path of doubt that can be exploited by defendants that want to get away with it.
From an extreme Constitutional standpoint, not releasing the source, which is in essence a method to describe how it works, the defendant is in a sense being accused of a crime by an unknown accuser of unknown credibility. At one point, the Sun revolved around the Earth, even when someone stood up to say it was wrong.
As prosecutors and law enforcement would routinely say, if you're innocent, what do you have to hide? There shouldn't be a double standard, guilt or innocence not withstanding.
At one point analyzing the lead in bullets to determine what batch of lead the slug came from was accepted as this so called "expert witness who has been trained and certified on a particular subject" but that was later determined to be invalid. But not after a lot of people were convicted by the technology.
I think we put far too much trust in technology, as if digitized data from man-made devices is somehow inherently free from error. In fact, I'd go as far as to say, that assuming our government would never purposely tamper with technology to achieve it's desired results isn't only in the realm of whack-job conspiracy theories (Nixon didn't seem to have much problem with it). The law may say we're innocent until proven guilty, but the public tends to think (as do some on this thread) that if you've been detained by the government (at any level) you must have done something to deserve detention. In some instances being arrested for a crime is all the proof needed to convict you of that crime, the rest is formality (if you've lived in a non-diverse rural community you may know what I'm talking about). The police are simply people, subject to all the foibles and petty motivations as the rest of us and anyone who thinks the police never arrest people falsely is a fool. Every DUI arrest report is practically a cut and paste job (at least in part) whether you're guilty or innocent. If you've ever paid attention to DUI reports when read on TV, or show up on cops, or in documentaries, or in the paper no matter what part of the country or who the arresting officer is, they all include something like this:
"At (time/date) I observed (defendant's name here) driving in an erratic manner . . . after approaching the car (name here) lowered the driver side window at which time I detected a distinct oder of alcohol on (name here's) breath . . . upon examining (name here's) eyes with my flashlight I observed (name here's) eyes appeared glassy and (name here's) pupils appeared dilated . . . upon questioning, (name here) exhibited signs of slurred speech and confusion . . ."
You can tell that some of the officers reading these statements (let's face it, their not all poet laureates), would never speak or write in the manner the reports are written on their own. Of course DUI arrestees share the same outward appearance so it will sound repetitive in reports, but these officers have been trained to include the same almost identical incriminating description of everyone they pull over regardless of the actual details as if they're copying it from a script.
Drunk driving is a dangerous crime and it should be dealt with accordingly. But when it comes down to it, the police can cut and paste anything they want into a police report. Once it's in writing, it carries a weight of it's own. Any policeman with a grudge against you, or simply doesn't like the color of your skin, the sound of your name, your face, or is just pissed because they pulled extra duty and feels like taking out on someone, can do anything they want to you. All they have to do is arrest you and write a report. It's your word as a fallible human being against another fallible human being who happens to have the authority to arrest you and put you in jail. Regardless of how you feel about drunk driving in general, I don't think we should be so quick to blindly trust our defense in any dealings with the law to depend upon a black box that is purchased by the system attempting to incarcerate you from an industry that makes money providing devices designed to assist in bringing about your incarceration.
I don't think "guilty beyond a reasonable doubt" and "guilty if a reasonable doubt is burdensome or inconvenient by the system to prove, so shut up and trust the magic box, it's digital so it can't be wrong" are the same thing.
And how is it that they can argue that challenging these breathylizers is "burdensome"? If we are innocent until proven guilty, the burden of proof is on the state. So, if this is burdensome for our overzealous police-state, too bad!
Most people don't know it, but the jury can chose to disregard the interpretation of the law if they find it to be not applicable, erroneously applied, or unjust for any reason.
I don't see the connection. Submitting a tax form does not incriminate a person.
I don't see the connection. Submitting a tax form does not incriminate a person.
If, as many people have been saying, the function of the breathalyzer is the same as all other units, then why does the source code supposedly contain "trade secrets" according to its manufacturer? Trade secrets, as in, it does something differently to all other units? Or trade secrets, as in "We don't want the bad publicity if a bug is found".
In this instance the code is a big part of the differentiating methodology. I do understand the point you are trying to make but I do not agree that releasing the code to the defense - and thereby putting it in the public record (essentially forcing it into the open source arena and allowing other manufacturers to profit from the R&D of the company) is the right way to handle this. If the code has been or could be verified by an independent 3rd party that would meet the needs of justice by having the report made part of the record without releasing trade secrets. Defense lawyers won't accept that though because they are, as is required by their ethical code, to zealously represent their client. They honestly don't care if the client is guilty or not of if the code is bug ridden or if the machine is even accurate. They just need a device by which they can defend their client. In this case it means demanding something that they know won't be made available to them and therefore getting their clients off by what could be rightly considered a technicality. I won't dint them for this - its their job after all. I will lambast anyone who thinks that this, in anyway, represents anything larger.
There are far better hooks to hang a story like this on.
- by Imalittleteapot February 5, 2009 4:00 AM PST
- They should be able to see the source code or have the case dropped. The reason though is because if they're really presumed innocent until guilty, we have to assume they're innocent. Ok if I assume their innocent, but the test comes up positive I have to wonder why. Maybe the test was broke? After all this person is innocent right? Well, I assumed he was? If you assume they're are then it must be the test that's defective. Therefore to prove them guilty we must be able to see the source code to show that no the test was not defective. Then at that point we know they really were guilty and that has been proven. However, without seeing the source and assuming innocence I have to make the assumption that the box was broke and they're not showing us the source code because they want to hide that fact from me. If you by innocent until prove guilty that's the only conclusion you can come up with. Any other conclusion is assuming they're guilty first.
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