Can you prove what someone's blood alcohol level would have been two hours ago based on what it is now?

September 1, 2009 9:10 AM

Can you prove what someone's blood alcohol level would have been two hours ago based on what it is now?

Pulled over and arrested then charged with DUI in the State of Vermont. Refused the roadside breathalyzer test. Took the roadside evaluation for shits and giggles (I think I did okay).

After much processing, asked to talk to public defender on call. Advised to consent to breath test, so I did. After much more processing, I finally took the breath test. I didn't take the test until two hours after the time of the stop.

My test results: 0.059%

Point at which it is a DUI: 0.080%

Charges dropped right? Not in this case. They are trying the case and the arresting officer claims they will bring in a chemist/scientist/whatever to say that based on my test results my blood alcohol level would have been above 0.080% at the time of the stop.

You are innocent until proven guilty right? Can they possibly "prove" this?

Several civil citations were given as well. One for not stopping at a stop sign (I did stop) and one for going over the yellow line (I may have). Also, a third was mailed to me for being two months out of inspection.

And to preempt the lawyer up advice. Of course I will be hiring a lawyer to represent me in this case, but I would like to know as much as I can going in, while I have plenty of time to get myself informed.

posted by anonymous to law & government (18 comments total)

It depends in part on your consumption prior to the test. Imagine if you had consumed a load of alcohol just before the test - your BAC would be headed up, not down. The cop probably asked you some relevant questions and they might try and use your answers in court.
posted by exogenous at 9:14 AM on September 1

Purely anecdotal story:

My mother sat on a jury that tried a case very similar to this one, except it was a guy who had been throwing a party on his house boat at a remote lake. Took several hours for the cops to get him to a facility where he blew around the same value as you.

Basically, the prosecutors can bring scientists in who will claim that they can extrapolate. Then your lawyer will bring people in to claim that they can't. It's up to the jury to decide if they like you or the cop better. In the case of my mother's jury, there were two more-or-less equal charges and after lots of debate I think they negotiated to find the defendant guilty of one and innocent of the other.
posted by muddgirl at 9:17 AM on September 1

They are trying the case and the arresting officer claims they will bring in a chemist/scientist/whatever to say that based on my test results my blood alcohol level would have been above 0.080% at the time of the stop.

Stop talking to or listening to the cops. Talk to and listen to your attorney/the public defender assigned to your case.
posted by muddgirl at 9:17 AM on September 1 [4 favorites]

Several DUI attorney sites (I know, not the best reference, but the first results in the google) suggest that the average person's BAC drops .015% per hour after stopping drinking. This book states that the descent of the BAC curve is linear, supporting extrapolation of prior concentrations but notes that there is some uncertainty. Whether or not this could be used to convict is of course best answered by your attorney.
posted by sanko at 9:20 AM on September 1

I don't know the law in Vermont, but in California - as I understand it - the BAC limit is not an innocent/guilty thing. If you are over 0.08% BAC in California, law enforcement is required bring charges of DUI. If you are under the 0.08% BAC, they are not required to bring charges, but if, in the opinion of the arresting officer, you are "impaired" regardless of your BAC, they can bring charges based on the officer's assessment.

That's why you can get a DUI even if your BAC is 0.02%, or even lower.

See a lawyer.
posted by Xoebe at 9:21 AM on September 1

Maybe Vermont has laws describing how the court can use Retrograde extrapolation?
posted by fritley at 9:21 AM on September 1

I sat on a jury that convicted a guy on a DWI charge - the case involved two malfunctioning breathalyzers and by the time they got him to the station to draw blood for an actual blood test, it was several hours after the traffic stop.

The evidence that we were presented with is basically that there is a narrow range of rates by which the body metabolizes alcohol (thus lowering the blood content), and given the time span involved in this case, either end of the range would have indicated that X hours ago, this guy was totally sauced. In other words, given a BAC at a point in time, you can work backwards and say with a fair amount of certainty that, say, two hours ago, the BAC was between X and Y. In this case, both X and Y were well above the legal limit.

It was a pretty clear cut case. So to answer your question, Yes.

Good luck.
posted by gyusan at 10:03 AM on September 1

[comments removed - you know where metatalk is.]
posted by jessamyn at 10:03 AM on September 1

The Vermont law has a section called "permissive inferences"...

23 V.S.A. § 1204. Permissive inferences
"If the person's alcohol concentration at that time was less than 0.08, such fact shall not give rise to any presumption or permissive inference that the person was or was not under the influence of intoxicating liquor, but such fact may be considered with other competent evidence in determining whether the person was under the influence of intoxicating liquor."

You're likely to lose your license for six months anyway...

23 V.S.A. § 1202. Consent to taking of tests to determine blood alcohol content
"Every person who operates, attempts to operate, or is in actual physical control of any
vehicle on a highway in this state is deemed to have given consent to an evidentiary test of that person's breath for the purpose of determining the person's alcohol concentration or the presence of other drug in the blood. The test shall be administered at the direction of a law enforcement officer."

So...
1. You failed the roadside check.
2. Vermont law doesn't give you a pass just because you're below the BAC limit.
3. You refused the breath test.

From a layperson's point of view, I think the best you can hope for is a lenient judge.
posted by DWRoelands at 10:04 AM on September 1

Oh, dammit. A source link:
http://www.totaldui.com/uploadedFiles/Total_DUI/State_DUI_Laws/Vermont/Vermont-DUI-Laws-Total-DUI.pdf
posted by DWRoelands at 10:05 AM on September 1

In other words, given a BAC at a point in time, you can work backwards and say with a fair amount of certainty that, say, two hours ago, the BAC was between X and Y. In this case, both X and Y were well above the legal limit.

Hardly, you're assuming BAC could only have decreased since the time of arrest. The OP could have had a BAC close to 0 at the time of arrest and a couple undigested beers sloshing around in his stomach. In that case, he wouldn't have been driving while intoxicated and could have a BAC of 0.059% a couple hours later.
posted by malp at 10:20 AM on September 1 [1 favorite]

DUI cases can be very complicated because of the science involved, the interaction of the various laws (over .08/impaired but under .08/implied consent), eligibility for diversion programs and civil penalties (will your license be suspended, etc.) This is exactly why lawyers handle DUI cases, and this is why a good private DUI lawyer will charge somewhere from $5,000 to $20,000 (in Oregon at least, no idea what the going rate is in Vermont.)

The advice about not talking to the police is good. Please don't take any other advice from this thread other than seeing a lawyer promptly. This sort of thing can be very complex and you don't want to get bad advice.
posted by Happydaz at 10:21 AM on September 1

And to preempt the lawyer up advice. Of course I will be hiring a lawyer to represent me in this case, but I would like to know as much as I can going in, while I have plenty of time to get myself informed.

Any information you get in this thread will need to be verified by a lawyer and can only serve to give you an undue impression of your case. Quit wasting your time looking for someone to tell you that everything is going to be okay and go talk to someone who might actually be able to help you.
posted by toomuchpete at 11:43 AM on September 1 [1 favorite]

You are innocent until proven guilty right? Can they possibly "prove" this?

Absolutely, humans metabolize alcohol in a predictable manner. You didnt hack the system by refusing to take the breathalyzer. Get yourself a decent lawyer and dont drink and drive.
posted by damn dirty ape at 12:27 PM on September 1

The OP could have had a BAC close to 0 at the time of arrest and a couple undigested beers sloshing around in his stomach. In that case, he wouldn't have been driving while intoxicated and could have a BAC of 0.059% a couple hours later.

Again, anecdotally: the defense attorney at the trial (where my mom was on the jury) tried to use this approach. I guess it worked on some of the jurists (the ones who like to drink a little before boating or driving), but it's a very hard sell if you start to think of the logistics. Burning off alcohol in the blood stream isn't dependent on concentration, but the rate of uptake into the bloodstream is. In other words, drinking a lot of alcohol in a short amount of time will raise a person's BAC much faster than drinking the same amount over a longer period of time. Either way, by the time the drinker gets from the bar to his car, his BAC should be roughly the same.
posted by muddgirl at 1:50 PM on September 1

muddgirl- yes, but with only one data point, you can't tell where in the curve he is. You can extrapolate one datapoint with a known rate, but in this case, there is more than one factor to consider. (Burnoff rate + uptake) Since the state can't prove what was in his stomach, they can't (shouldn't be able to) convict him based solely on that.

Now if the driver did *anything else* that provided evidence he was intoxicated, then he can and should be convicted of something.

Actually, refusing to take the breathalyzer is hacking the system. You cannot be compelled to provide evidence against yourself without [some legal mechanism]. Otherwise, you wouldn't be able to refuse. That's exactly why most states enacted laws that say it's a whole different crime to refuse to take a breathalyzer. You are free to refuse to the search, but in doing so you violate the terms of your license and it gets suspended for some amount of time. Usually the same amount of time a dui will get you...
posted by gjc at 4:41 PM on September 1

I am a criminal defense attorney practicing in Vermont and I have represented many people charged with driving under the influence. I would be happy to field your questions so that you are informed before speaking to your attorney or the judge. Although you may have some time before your arraignment on the criminal case, please be aware that you may have to request a civil suspension hearing immediately to prevent the DMV from suspending your license. Send me a "Metafilter mail" if you would like to talk tomorrow. I hate to see my people in trouble!
posted by kellygreen at 8:10 PM on September 1

Belatedly: Don't just hire "a lawyer", get someone with a lot of experience with this type of case. That means you don't want a generalist, and you don't want (in all probability) to hire someone that you or a family member knows. Experience is critical not only if the case goes to trial, but - possibly even more importantly - in negotiating with the prosecuting attorney. It may well be that your best option is to plead "no contest" in exchange for a suspended sentence, since you may be risking jail time if you go to trial. (Your lawyer's fees are likely to be much higher if you go to trial, too.)
posted by WestCoaster at 5:21 PM on September 9