Beating Positive Breathalyzer Results: Why Breathalyzer Tests Can Be Wrong

 We all know that drinking and driving is never a good idea.  There is no excuse for getting drunk and getting behind the wheel of a car.  However, what if you only had one drink or a sip of alcohol, even none at all, and you tested positive on a breathalyzer test?  This type of thing happens more than you think.  Recently in San Francisco over 1,000 false positive readings were thrown out, and prosecutions overturned because of such results. 

How can Breathalyzers Yield False Positive Results? 

1.        Improper Breathalyzer Calibration

Improper calibration was the main cause of the over 1,000 conviction turnovers in San Francisco last spring.  Every make and model is different, and law enforcement divisions must follow the equipment manufacturer’s guidelines for calibration exactly for the results to be accurate.  In the California incident, the 20 breathalyzer units were supposed to be calibrated every two weeks.  However, San Francisco law enforcement failed to maintain the equipment manufacturer’s guidelines and was forced to overturn hundreds of convictions based on the outcome of the breathalyzer test results.

2.        Alcohol Residue in Mouth

This may sound silly, but a breathalyzer is designed to measure the amount of alcohol saturation from the air in a person’s lungs.  The human body releases alcohol through the lungs as a way of processing and expelling it.  If a person has just taken a sip of alcohol, they will have residual alcohol in their mouths that the breathalyzer assumes is from the lungs.  This can yield a much higher reading than the actual amount of alcohol in the person’s body. Therefore, each breathalyzer recommends that the testing officer wait a certain period of time (usually about 20 minutes) before administering the test for accurate results.  If you have just downed half a glass of wine before getting pulled over, the residual alcohol in your mouth will mislead the breathalyzer into thinking you just drank an entire bottle.

3.        Breathalyzer Interference

Many things can cause false positive readings on breathalyzer tests, the most common being an elevated number of ketones in diabetics’ blood that causes an increase in acetone in their breath.  Some breathalyzer tests are sensitive to acetone and mistakenly register it as alcohol.  Other substances can cause false positive results as well such as paint fumes, chemical fumes, mouthwash, gum, cough syrup, and even herbal supplements. 

4.        Other Breathalyzer Reading Errors

A breathalyzer can also improperly measure BAC during the absorption phase of alcohol consumption. Absorption time varies depending on the person, but it can last anywhere from half an hour to two hours.  In the absorption period, alcohol is not evenly distributed through the blood stream and can yield erroneous breathalyzer results. 

Did You Test Positive for Alcohol on a Breathalyzer Test?

If you tested positive on a breathalyzer test you need to contact a DWI lawyer immediately to start building your defense.  Only an experienced DWI lawyer will have the knowledge and expertise necessary to fight for you in court.  If you are facing DWI or DUI charges after testing positive on a breathalyzer test, hire a DWI  or DUI lawyer today. 

 

 

 

 We all know that drinking and driving is never a good idea.  There is no excuse for getting drunk and getting behind the wheel of a car.  However, what if you only had one drink or a sip of alcohol, even none at all, and you tested positive on a breathalyzer test?  This type of thing happens more than you think.  Recently in San Francisco over 1,000 false positive readings were thrown out, and prosecutions overturned because of such results. 

How can Breathalyzers Yield False Positive Results? 

1.        Improper Breathalyzer Calibration

Improper calibration was the main cause of the over 1,000 conviction turnovers in San Francisco last spring.  Every make and model is different, and law enforcement divisions must follow the equipment manufacturer’s guidelines for calibration exactly for the results to be accurate.  In the California incident, the 20 breathalyzer units were supposed to be calibrated every two weeks.  However, San Francisco law enforcement failed to maintain the equipment manufacturer’s guidelines and was forced to overturn hundreds of convictions based on the outcome of the breathalyzer test results.

2.        Alcohol Residue in Mouth

This may sound silly, but a breathalyzer is designed to measure the amount of alcohol saturation from the air in a person’s lungs.  The human body releases alcohol through the lungs as a way of processing and expelling it.  If a person has just taken a sip of alcohol, they will have residual alcohol in their mouths that the breathalyzer assumes is from the lungs.  This can yield a much higher reading than the actual amount of alcohol in the person’s body. Therefore, each breathalyzer recommends that the testing officer wait a certain period of time (usually about 20 minutes) before administering the test for accurate results.  If you have just downed half a glass of wine before getting pulled over, the residual alcohol in your mouth will mislead the breathalyzer into thinking you just drank an entire bottle.

3.        Breathalyzer Interference

Many things can cause false positive readings on breathalyzer tests, the most common being an elevated number of ketones in diabetics’ blood that causes an increase in acetone in their breath.  Some breathalyzer tests are sensitive to acetone and mistakenly register it as alcohol.  Other substances can cause false positive results as well such as paint fumes, chemical fumes, mouthwash, gum, cough syrup, and even herbal supplements. 

4.        Other Breathalyzer Reading Errors

A breathalyzer can also improperly measure BAC during the absorption phase of alcohol consumption. Absorption time varies depending on the person, but it can last anywhere from half an hour to two hours.  In the absorption period, alcohol is not evenly distributed through the blood stream and can yield erroneous breathalyzer results. 

Did You Test Positive for Alcohol on a Breathalyzer Test?

If you tested positive on a breathalyzer test you need to contact a DWI lawyer immediately to start building your defense.  Only an experienced DWI lawyer will have the knowledge and expertise necessary to fight for you in court.  If you are facing DWI or DUI charges after testing positive on a breathalyzer test, hire a DWI or DUI lawyer today. 

 

 

 

Why has it taken Harris County so long to tell us they won't oppose a new trial for those cases with fake breath tests?

Deetrice Wallace, the technical supervisor responsible for maintaining the integrity of the breath test machines used by law enforcement to convict arrestees of DWI, will be spending the next year behind bars for faking inspections on the breath test machines.

I have spoken to Ms. Wallace on many occasions over the past few years as we have obtained information about the breath testing machines that she inspected.  She seemed like a nice enough person and was always forthcoming with the information that we requested.  She even requested that the payments for the records go to a Boy Scout Troop.  I'm not sure what led her to fake the results of the tests, but it sure has had a huge impact on many DWI client's lives.

The real question that I have is why has it taken so long for Harris County to say that they will not oppose a new trial for those that were affected by the fake tests?  Galveston County sent me a list of my Galveston DWI clients that took a breath test where Deetrice Wallace had maintained the breathalyzer back on January 15, 2009.  Harris County still has not sent me a list of my clients that are affected by Deetrice Wallace.  We have had to re-create that list on our own.

Toyota developing new technology for DWI and drunk driving

According to a yahoo article, Toyota is in the process of developing technology to combat drunk driving in commercial vehicles.  The device that they are currently testing would have a hand-held breathalyzer that detects alcohol in a persons breath and prevent the vehicle from being started if the level of alcohol is over a certain amount.   The article goes on to state that there will be a camera to verify the person that has blown into the machine.

Funny thing about this article is the technology already exists and is being used in DWI cases every day here in Houston.  The only difference is that the technology used here in Texas is "after market," not original to the vehicle.  Go see my friends at EZ Interlock if you are interested in the technology that is already on the market. 

The Harris County courts are using this technology more and more often.  My concern is that Big Brother is getting bigger and bigger.  I think it is very possible that Big Brother may mandate this type of technology for everyone at some point in our history, and that is just frightening.  What else is Big Brother going to mandate - that we all GPS technology in our vehicles so they can know where we are at all times?