Monday, June 30, 2008

Temperature's Rising

One of the most neglected areas of attack upon the Intoxilyzer 5000 by Texas criminal defense lawyers defending DWIs is the assumption the temperature of a DWI suspect's breath is 34 degrees Centigrade (or 93.2 degrees Fahrenheit).

Heat is the driving force behind
Henry's Law and the inner workings of the Intoxilyzer 5000. Heat causes the ethanol in a person's blood to evaporate into their breath inside the lungs. The higher the temperature, the more ethanol goes into the breath.

The Intoxilyzer 5000 is certified to give accurate results for water solutions (the reference sample) of ethanol carefully maintained at a temperature different from the human body. However, the machine is never checked for accuracy using samples provided by living human beings at a core body temperature of 98.6 degrees Fahrenheit.

The Intoxilyzer programing assumes the breath temperature from a DWI suspect is 93.2 F. But not all investigators agree that expired human breath is at this temperature. This is critical since the higher the core body temperature, and thus higher breath temperature, the more the Intoxilyzer will
overestimate the breath alcohol concentration of the person providing a sample. Amazingly, the Intoxilyzer as no way to measure a person's breath temperature at the time a sample is collected.

Studies show for every 1.8 degree Fahrenheit (1 degree C) increase in breath temperature there is a 6.8%
overestimation of the measured breath alcohol, compared to that of a simultaneous blood alcohol sample. This means an Intoxilyzer 5000, measuring a person blowing into the machine with a breath temperature of 98.6 degrees F, is calculating an ethanol concentration about 20% too high. Consequently, many persons providing breath samples are being unjustly charged with DWI and are being wrongly convicted.

Next time we'll look at the Intoxilyzer 5000 and organic chemical interference.

Friday, June 27, 2008

More On Henry's Law

Earlier this week I posted here about the problems with the Intoxilyzer 5000. This machine is used nationwide by law enforcement to obtain breath samples from DWI suspects and to analyze the sample for ethanol concentration. More on Henry's Law.

The reference sample device on the Intoxilyzer is designed to deliver a sample of vapor containing a known or predicted amount of ethyl alcohol (ethanol). The reference sample device is supposedly used to verify the accuracy and calibration of the machine. A reference analysis is conducted as a part of each subject test to ensure the machine is properly calibrated.

The theory of operation of the reference sample device is based upon Henry's Law. In a closed system, like the diagram above, the amount of ethanol in the airspace above a liquid (lavender dots) is proportional to the amount of ethanol in the liquid (blue dots). Henry's law applies to closed systems at a given temperature and pressure. The Intoxilyzer 5000 does a good job at accurately predicting the amount of ethanol in the reference sample.

However, when the Intoxilyzer 5000 is used to predict the amount of ethanol in human breath the situation changes dramatically. If you assume the liquid in the closed system illustrated here is human blood, and the airspace illustrated is the air in the lungs, even a lay person can quickly recognize potential problems.

First, the human lung is not a closed system. Pressure in the lungs is constantly changing as we inhale and exhale. As the pressure changes so does the amount of ethanol in the airspace above the blood in our lungs. Furthermore, the temperature of the system is critical. If the solution temperature is low, the results will be low. If the solution temperature is high, the results will be high.

The problem with the Intoxilyzer 5000? It assumes a constant pressure and it assumes a predicted temperature within the system. If the pressure is changing then Henry's Law can only be used to approximate the concentration of ethanol in human breath. Moreover, the Intoxilyzer does not measure the temperature of the suspect's breath sample. Without knowing the precise temperature the Intoxilyzer can only make assumptions that might not bear out in a particular case. If the temperature of the person's breath is different than what the machine assumes it is, then the results obtained will be erroneous.

More about temperature problems in a later post.

Wednesday, June 25, 2008

The Intoxilyzer 5000

Fellow defense lawyer, Mark Bennett, started a Texas DWI breathtest case this week. Here's what I hope Mark knows about the Intoxilyzer 5000:

1. The Intoxilyzer 5000 is designed to analyze a sample of a person's breath based on Henry's law. When a volatile chemical (ethanol) is dissolved in a liquid (blood) and brought into contact with a CLOSED air space, an equilibrium is formed and there exists a FIXED RATIO between the concentration of ethanol in the air space and the concentration in the liquid. (at a given temperature and pressure) At equilibrium one can measure the concentration of ethanol in the gas phase and predict the concentration of ethanol in the liquid. The problem with the human lungs? They are not a closed system and Henry's law does not exactly apply.

2. The Intoxilyzer is designed to produce a breath alcohol result exactly corresponding to a simultaneous blood alcohol sample. The problem is the assumption that the partitioning of alcohol from the blood into the breath is 2100:1. Not all persons partition alcohol from their blood based upon this ratio. Studies show partition ratios as low as 834:1. The Intoxilyzer 5000 will overestimate the alcohol concentration of someone blowing with a partition ratio less than 2100:1.

3. The Intoxilyzer 5000 assumes the test subject is in the elimination phase, rather than the absorption phase. It is rarely known whether the person is still absorbing alcohol from their last drink when the breath test is administered.

4. The Intoxilyzer assumes the temperature of the person's exhaled breath is 34 degrees Centigrade. Core body temperature for humans is 37 degrees Centigrade. For every breath degree over 34, the Intoxilyzer 5000 overestimates the breath alcohol content by about 6.8%. Moreover, the machine is not designed to measure the temperature of the suspect's breath.

5. Mouth alcohol can lead to erroneous breath sample results. The Intoxilyzer 5000 claims to handle the mouth alcohol problem with a computer program called the "slope detector." There have been no scientific, peer reviewed studies showing the slope detector works as advertised.

6. As Mark stated in his blog post, the margin of error for the Intoxilyzer 5000 is +/- 0.010 for the reference sample, and +/- 0.020 for the suspect's breath sample.

7. Beyond this, the sample chamber can have up to .019 gms alcohol/210 liters breath alcohol inside when the machine is reading a 0.00.

There are other problems with the Intoxilyzer 5000. I hope Mark is using these blatant problems to his client's advantage this week during trial.

From His Porch

My friend and fellow defense lawyer, Mark Bennett was interviewed by reporter, Mary Flood, from the Houston Chronicle. Mark's interview is here and worth reading. Mark also looks pretty good standing on his front porch either leaving for, or coming from, the courthouse.

Tuesday, June 10, 2008

From Bear Crawls to Courtroom Paddlings

Last month I wrote here about an incident with my son at his elementary school. He was required to perform bear-crawls (corporal punishment) as discipline for misbehaving.

Now a Texas judge has been sued for giving parents the option of paddling their children in open court. The Brownsville Herald reported that judge Gustavo Garza was giving parents the option of spanking their children for truant behavior, or have the child face criminal charge and fines. The Associated Press reported a preliminary injunction was sought to stop Garza's use of paddles in his courtroom. Check out the video from News Channel 5 (KRGV) for a picture of the offending lumber.

Certainly a novel approach for rehabilitating truant youngsters in South Texas. What do you think? A good paddling vs. a juvenile adjudication and fines. To harsh? Over the top? Maybe a courageously good idea? I'd love to hear what you think.

Monday, June 9, 2008

Sumbit Your Photo Now

So what do you think about this story? Howie Altholtz, Boston attorney and marketing director at Ruberto, Israel, and Weiner PC wants to publish a glossy pinup calendar featuring attractive male and female attorneys to benefit charity, that is, the Greater Boston Legal Services. Altholtz developed a website (Beautiful Lawyers) through which pinup hopefuls can submit their photographs, or photographs of others, for review and possible publication in the calendar.

The ABA Journal posted a piece (no pun intended) commenting on Altholtz's intriguing idea for raising money for a good cause. A sharp (but post-feminist) comment by attorney Ellen Barshevsky set the tone for some great discussion:
Why do WE always have to be objectivized? You know these men only want to see pretty women in skimpy bathing suits , and I’ll bet most of the men will be dressed to the nine’s in their 6 piece suits. Also, why is it that these people are focusing on physical beauty, when it is our MINDS that differentiate us from other bimbos. I went to law school to be a professional, not to show off my body to anyone. I would NOT buy this calendar product, even though it purports to be gender neutral and for a good cause. Face it, without pretty WOMEN, no one will buy it to see the guys. Women should NOT be viewed as MEAT.
So what do you think? Good fun or another blatant exploitation of the beautiful female (and male?) form?

Taking Your Medicine

Sometimes we need to take what is coming around. Since I'm a believer in the Biblical adage about "reaping" what we "sow," I'm surprised Austin, Texas criminal defense lawyer, Adam Reposa, is not just taking his medicine after being found in contempt of court for making a lewd gesture in court while discussing a plea bargain with prosecutors and a county court at law judge.

Last April the Austin American-Statesman reported here about the civil contempt hearing in which Reposa was alleged to have made a gesture simulating masturbation while in open court. He was sentenced to 90 days in the county jail, as a result. The ABA Journal reported today that Reposa was appealing his sentence to the Texas Court of Criminal Appeals.

Ninety days in county seems fair to me for something as stupid as this. Heck, even Reposa was reported to have believed the sentence was fair while he was escorted out of the courtroom in handcuffs at the conclusion of the contempt hearing. This guy ought to take his medicine and stop wasting the court's time.

Why so hard on my fellow defense lawyer this early Monday morning? Guys like Reposa give hardworking, ethical, and committed defense lawyers a bad name. There's a price to pay for utter stupidity and what's coming around for Reposa seems earned to me.