Recently, our CCL Judge has begun to take judicial notice of the intoxilyzer 5000 instrument. This has the effect of preventing the defense from cross-examining the tech supervisor on the science or technique behind the instrument itself to measure breath/alcohol ratio. They can still question whether the actual testing was done properly and whether it had been properly maintained.

There is a CCA case on this (Beard) but it was pulled down after the D died. Has anyone else seen this? The local defense bar says it prevents an individual from putting on a defense and thus violates due process. Its currently on appeal so we'll all see soon.

-jbm

What's the difference between the trial court judge taking judicial notice that the technology in the Intoxilzyer 5000 is reliable for the purpose of testing a subject's blood alcohol concentration and the Court of Criminal Appeals taking judicial notice of the scientific reliability of the horizontal gaze nystagmus test for detecting the presence of alcohol in a subject's blood?

Janette Ansolabehere

Everyone should remember, the Intoxilyzer measures a persons BREATH alcohol concentration, not blood alcohol. While the 2 values are related, and often times very close when compared to one-another, they are in fact, 2 different samples and when both are measured at the same time, you can, and often do, get slightly different results.

I often correct young prosecutors, and defense council who mis-speak and make refernce to the intoxilyzer measuring blood alcohol concentrations.....terminology matters!

Forensic Scientist is correct--the Intoxilyzer 5000 does measure the level of alcohol in the breath,not the blood (the Penal Code refers to as "alcohol concentration.") And of course, terminology is important. (That's what happens when you are typing really fast because you have to leave and you're late!).

I believe that a court can take judicial notice that the methadology of the Intoxilyzer is reliable for measuring breath alcohol level just as the CCA did with the HGN field sobriety test. That said, I just wonder how long it will be before Texas prosecutors have to deal with the issue of Intoxilzyer source code as has been the case with some--but not all courts--in Florida and a couple of other states.

Janette Ansolabehere

Howstuffworks says the Intoxilyzer actually measures a sample's absorption of infrared light.

The presence of alcohol is inferred from the absorption spectrum.

http://science.howstuffworks.com/breathalyzer4.htm

Gee, I should have read "howstuffworks".....instead I wasted 10 years of my life in formal education (specializing in biochemistry and infrared spectroscopy) and another 12 years working in the world of forensics.....silly me.

quote:

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Originally posted by David Newell:
i often feel the same way about the law.

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I often feel the same way about Newell's taste in music.

Forensic Scientist - 1

Software Engineer - 0

I wasn't trying to score points or depreciate the value of your studies and experience.

It seems like a semantics game to say the Intoxilyzer measures breath alcohol rather than blood alcohol... when the primary reason we care about the breath alcohol is what it allows us to infer about blood alcohol...

Could you not just as honestly say that the Intoxilyzer actually measures the intensity of certain wavelengths of infrared light after the light passes through a breath sample?

[QUOTE]Originally posted by AlexLayman:

It seems like a semantics game to say the Intoxilyzer measures breath alcohol rather than blood alcohol... when the primary reason we care about the breath alcohol is what it allows us to infer about blood alcohol...QUOTE]

Who is "us"?

"Could you not just as honestly say that the Intoxilyzer actually measures the intensity of certain wavelengths of infrared light after the light passes through a breath sample? "

let me go check and see what "howstuffworks" says....

The importance of the distinction (and it is important) between whether we refere to the INtoxylizer result as a breath or blood concentration is that the LAW makes the distinction. Breath alcohol and blood alcohol are two different means of proof of intoxication under the definition of alcohol concentration. Breath test evidence, while it might allow for an inference of blood alcohol concentration, is direct evidence of breath alcohol concentration. So even if you had a case where breath alcohol is over .08 and blood alcohol was less than .08, that defendant is guilty under the statute. It confuses the issue to suggest that you have proven "blood alcohol concentration" when your evidence is of "breath alcohol concentration."

well stated.

No right to speak with scientific authority here, but..... We need to be able to communicate to juries (Scientist and lawyers alike) that breath alcohol concentration is important because as a matter of scientific certainty it relates to the amount of alcohol in the persons blood. We have lost the battle of public opinion on breath testing. That is right the bad guys won and the good guys lost. When the test vary it is almost always the breath test that benefits the defendant, not due to invalid science, but rather the difficulty of obtaining the deep lung sample necessary for testing.

I know the tone here is playful, but our "failure to communicate" results in the bad guys winning fights they shouldn't.