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Arizona DUI Defense Blog  

What Do Field Sobriety Tests Prove? - Mon, 29 Jun 2009 12:53:02 -0700

The short answer is not much. At best, they may correlate to someone having a blood alcohol concentration over a .08. At worst, they prove nothing at all. To understand their meaning you must look at how they came into existence and who developed them.

In the late 1970’s NHTSA (the National Highway and Traffic Administration) paid for some research to see if tools could be developed for law enforcement to identify people who are potentially DUI / DWI.

There were several studies paid for by the government. Specifically, there are six primary studies relied on by law enforcement. However, none of the studies have been subject to peer review.

1977 Study (Not Peer Reviewed)

1981 Study (Not Peer Reviewed)

1983 Study (Not Peer Reviewed)

Colorado Study (Not Peer Reviewed)

Florida Study (Not Peer Reviewed)

San Diego (Not Peer Reviewed)

According to Wikipedia, peer review has been defined as:

 

...the process of subjecting an author's scholarly work, research, or ideas to the scrutiny of others who are experts in the same field. Peer review requires a community of experts in a given (and often narrowly defined) field, who are qualified and able to perform impartial review...Pragmatically, peer review refers to the work done during the screening of submitted manuscripts and funding applications. This process encourages authors to meet the accepted standards of their discipline and prevents the dissemination of irrelevant findings, unwarranted claims, unacceptable interpretations, and personal views. Publications that have not undergone peer review are likely to be regarded with suspicion by scholars and professionals.

Thus, the research has not been subject to scrutiny in the scientific community and begs the question why not? Only the government can answer this question.

So what does the government say these studies show? Unfortunately, much of law enforcement does not even know what their own research says. If you ask most officers who regularly conduct DUI investigations, they will tell you that field sobriety tests show “impairment.”

However, the government’s own research concludes this is not the case. If you are willing to accept these non-peer reviewed studies, then you may merely conclude that a poor performance correlates to a blood alcohol concentration above a .08. Moreover, the tests were previously used to show a blood alcohol concentration above a .10. Then the law changed in several jurisdictions and somehow it also changed scientific results.

Consequently, if you believe NHTSA’s own research, these agility tests do not show impairment. There merely make it appear to show impairment. 

A Person Accused Of DUI Deserves A True Second Opinion - Mon, 15 Jun 2009 18:08:27 -0700

Arizona DUI cases almost always involve a chemical test. There is a movement in Arizona towards the exclusive use of blood testing. It is well settled that blood testing is more accurate than breath testing. But how accurate is blood testing? Can it truly determine a person's blood alcohol concentration? I believe that these are reasonable questions to be asked by a person accused of DUI and facing 30 to 45 days in jail.

Under our system of justice we should demand better answers from the government than "because we said so" or "because our lab has the highest standards." Simple conclusions are not good enough in science and they should not be good enough in justice.

So who checks the government's test results in Arizona? The simple answer is the government. They merely claim to check themselves. I have yet to see one Arizona crime lab that conducts blind testing by an independent party.

Here is how the actual process works. In Arizona DUI cases, The government expert will tell juries that they do double check their work. That is, they have a quality assurance program to make sure the blood alcohol test results are accurate. But the government's oversight of their work is not what you my think. Instead retesting every sample, or randomly retesting a portion of the samples, the lab merely does a technical review.

A "technical review" is not retesting. The Government toxicologist usually puts between 30 to 40 blood samples into a blood tester. Then they turn the blood tester on and leave. The blood tester commonly runs overnight and the printed results are reviewed by the government lab person.

 

This review of the printed documents is what is known as a technical review. The actual documents are called chromatograms. They are simply pieces of paper with graphs and data on them (retention times, area counts, etc...) If the run has the usual 30 to 40 samples there could be well over 100 pages of data.

In court, the government will tell the jury that they "double check" all the tests. What they actually do is take those 80 to 100 pieces of paper and give it to another employee of the same lab.  That person then reviews the data. As long as the data appears to be consistent, they conclude it is an accurate test. In Court, they tell the jury they got a second opinon from another analyst to ensure the accuaracy of the tests.  

A nationally recognized expert, Dr. A.W. Jones, has opined that in forensic testing of blood samples retesting should be done, not a mere a "technical review." It is his opinion, that a mere technical review is inadequate to ensure the accuracy of the test results.

This standard makes perfect sense in DUI cases because the level of punishment is often dependent upon the test result. If a person's blood alcohol concentration result is .165 the person is facing a minimum of 30 days in jail. If he was under a .150 then he is merely facing 1 day in jail. Is it too much to ask the government to check their work when 29 days of jail is at stake? I guess the answer depends on how important the result is to you.

If you were at the doctor and she said "the blood tests were back," "we need to operate," let's "prep for the mastectomy." Most people would seek a second opinion. Why...because the issue is too important to merely rely on the first test. When it matter to you - you retest.

P.S. I will address the Defendant's ability to do their own retesting in my next entry.

 

A Well Written Post on The Source Code Issue - Mon, 26 Jan 2009 20:44:46 -0700

I ran across an excellent post discussing the source code issue.  That is, the fight between criminal defense attorneys and the maker of the breath tester (CMI) to disclose the code used in their breath testers.  CMI will not allow an inspection of the code.  Consequently, it cannot be checked for accuracy.  CMI essentially tells everyone charged with DUI to "just trust us."

Ed Brayton, a journalist and the co-founder of Michigan Citizens for Science, discusses the source code litigation in Florida.

Here's a very interesting case from Florida, where an appeals court has upheld a lower court ruling that threw out evidence from a breathalyzer test in a drunk driving case because the manufacturer of the device refused to release the source code and allow defense experts to analyze the accuracy of the machines.

The results of breath tests in more than 100 local drunken-driving cases will not be allowed at trial, a judge announced Tuesday.

The validity of those breathalyzer tests has been challenged for more than three years because of the Intoxilyzer 5000, a machine that uses a breath sample to measure a person's blood-alcohol content.

Manatee County Judge Doug Henderson ruled two years ago that any Intoxilyzer 5000 tests were inadmissible in trial, but prosecutors appealed. On Tuesday, Henderson told lawyers that his ruling had been affirmed by the Second District Court of Appeal and Circuit Court.

Breath analysis machines are notoriously inaccurate and this has been a problem for a very long time. Dr. David Hanson, a sociologist who has written on this issue for decades, writes:

Breath analyzers (Breathalyzer, Intoxilyzer, Alcosensor, Alcoscan and BAC Datamaster are common brand names) don't actually test blood alcohol concentration (BAC), which requires the analysis of a blood sample. Instead, they estimate BAC indirectly. Different types of machine use different techniqes and larger machines generally yield better estimates than do hand-held models. Therefore, some states don't permit data or "readings" from hand-held machines to be presented as evidence in court. South Dakota does not even permit evidence from any type or size breath tester but relies entirely on blood tests to ensure accuracy and protect the innocent.

A major problem with some machines is that they not only identify the ethyl alcohol (or ethanol) found in alcohol beverages, but also other substances similar in molecular structure. Those machines identify any compound containing the methyl group structure. Over one hundred compounds can be found in the human breath at any one time and 70 to 80 percent of them contain methyl group structure and will be incorrectly detected as ethyl alcohol. Important is the fact that the more different ethyl group substances the machine detects, the higher will be the false BAC estimate.

The National Highway Traffic Safety Administration (NHTSA) has found that dieters and diabetics can have acetone levels hundreds and even thousand of times higher than that in others. Acetone is one of the many substances that can be falsely identified as ethyl alcohol by some breath machines.

One investigator has reported that alcohol-free subjects can generate BAC readings of about .05 after eating various types of bread products.

Substances in the environment can also lead to false BAC readings. For example, an alcohol-free subject was asked to apply a pint of contact cement to a piece of plywood and then to apply a gallon of oil-base paint to a wall. The total activity lasted about an hour. Twenty minutes later the subject was tested on an Intoxilyzer, which registered a BAC of .12 percent. This level is 50% higher than a BAC of .08, which constitutes legal intoxication in many states.

Similarly, a painter with a protective mask spray painted a room for 20 minutes. Although a blood test showed no alcohol, an Intoxilyzer falsely reported his BAC as .075.

Any number of other products found in the environment can cause erroneous BAC results. These include compounds found in lacquers, paint removers, celluloid, gasoline, and cleaning fluids.

Other common things that can cause false BAC levels are alcohol, blood or vomit in the subject's mouth, electrical interference from cell phones and police radios, tobacco smoke, dirt, and moisture.

Breath testers can be very sensitive to temperature and will give false reasings if not adjusted or recalibrated to account for ambient or surrounding air temperatures. The temperature of the subject is also very important. Each one degree of body temperature above normal will cause a substantial elevation (about 8%) in apparent BAC.

Many breath testing machines asume a 2,100-to-1 ratio in converting alcohol in the breath to estimates of alcohol in the blood. However, this ratio varies from 1,900 to 2,400 among people and also within a person over time. This variation will lead to false BAC readings.

Physical activity and hyperventilation can lower apparent BAC levels. One study found that the BAC readings of subjects decreased 11 to 14% after running up one flight of stairs and 22-25% after doing so twice. Another study found a 15% decrease in BAC readings after vigorous exercise or hyperventilaion.

Some breath analysis machinnes assume a hematocrit (cell volume of blood) of 47%. However, hematocrit values range from 42 to 52% in men and from 37 to 47% in women. A person with a lower hematocrit will have a falsely high BAC reading.

It's about time a judge took a stand on this issue.

I Need to Hire the Guy that Made This Video. - Sat, 03 Jan 2009 06:01:47 -0700

Here is a very well researched and produced video regarding an Ohio DUI case.  While I do not agree with everything he argues, her certainly makes some vaild points.  Enjoy:

 

Please Think About This Before You Drink And Drive This Holiday Season - Sat, 20 Dec 2008 10:14:56 -0700

There is significantly more drinking and driving during the holidays.  It happens every year, in every place.  I have plenty of business.  However, I don't want you to become a customer. Trust me, you have better things to do than hang out with me in a courtroom for the next three or four months.  Thus, I am going to republish a post that I have previously written.  The post is titled: "3 Things I Wish People Knew Before Drinking & Driving."

Before you read the post, please watch this video.  The story is more persuasive than anything I could ever write.

 

 

This post was originally published on 07/31/08:

It's 5:00 p.m. on Friday afternoon in Phoenix, and Joe just walked through the door of his favorite restaurant to meet some friends for happy hour.  He drove himself to the restaurant.  When he is done, he is going to drive to his house in Scottsdale.

At the table, Joe sees everyone has one of the restaurant's signature margaritas in front of them.  The waiter comes to the table and asks Joe: "can I get you something to drink?"  Before Joe answers this question, I wish he would consider the following facts:

1. There is no crime of Drunk Driving in Arizona.  Arizona law makes it illegal to drive while Joe is impaired to at least the slightest degree by alcohol.  This means that if Joe's ability to drive is impaired to any degree, Joe is technically in violation of the law;
2. If Joe is stopped by the police, they will stick a needle in Joe's arm.  Regardless of the law on this subject, it has been my experience that if Joe is stopped by a police officer for a traffic violation, and the officer smells any alcohol, Joe is going to end up taking a chemical test.  Many police agencies are now using blood testing instead of breath testing.  If the officer smells alcohol on Joe's breath (or just imagines it), Joe is going to have a needle stuck in his arm and a blood sample will be taken.  The results of the blood test will probably take at least 30 days to come back.  While Joe is waiting to find out the results of the blood test, he will not sleep very much or very well;
3. If Joe refuses the blood test, the officer will get a warrant and forcibly take his blood.  Once the officer meets the requirements of Arizona's implied consent law, he may require Joe to submit to a chemical test.  If Joe says "no," he will then lose his driver's license for 12 months.  Moreover, the officer will then make a phone call to the judge.  Within minutes, the judge can then issue a telephonic warrant.  If Joe still refuses, he will be held down by several police officers, and a needle will be shoved into his vein. 

Now if Joe knew these three things when the waiter asked him: "can I get you something to drink" - how might Joe answer?  I think the average Joe would say: "Yes...Diet Coke."

Please consider the above before you drink and drive.  Moreover, if you know someone who needs to become aware of these "3 Things" please use the "email this post" button at the bottom and send it to them.  This is a subtle way of possibly preventing a life changing tragedy. Thanks!

Added on: 29-Nov-2008
Hits: 73
Rate this RSS/Atom Feed

Arizona DUI Defense Blog  

What Do Field Sobriety Tests Prove? - Mon, 29 Jun 2009 12:53:02 -0700

The short answer is not much. At best, they may correlate to someone having a blood alcohol concentration over a .08. At worst, they prove nothing at all. To understand their meaning you must look at how they came into existence and who developed them.

In the late 1970’s NHTSA (the National Highway and Traffic Administration) paid for some research to see if tools could be developed for law enforcement to identify people who are potentially DUI / DWI.

There were several studies paid for by the government. Specifically, there are six primary studies relied on by law enforcement. However, none of the studies have been subject to peer review.

1977 Study (Not Peer Reviewed)

1981 Study (Not Peer Reviewed)

1983 Study (Not Peer Reviewed)

Colorado Study (Not Peer Reviewed)

Florida Study (Not Peer Reviewed)

San Diego (Not Peer Reviewed)

According to Wikipedia, peer review has been defined as:

 

...the process of subjecting an author's scholarly work, research, or ideas to the scrutiny of others who are experts in the same field. Peer review requires a community of experts in a given (and often narrowly defined) field, who are qualified and able to perform impartial review...Pragmatically, peer review refers to the work done during the screening of submitted manuscripts and funding applications. This process encourages authors to meet the accepted standards of their discipline and prevents the dissemination of irrelevant findings, unwarranted claims, unacceptable interpretations, and personal views. Publications that have not undergone peer review are likely to be regarded with suspicion by scholars and professionals.

Thus, the research has not been subject to scrutiny in the scientific community and begs the question why not? Only the government can answer this question.

So what does the government say these studies show? Unfortunately, much of law enforcement does not even know what their own research says. If you ask most officers who regularly conduct DUI investigations, they will tell you that field sobriety tests show “impairment.”

However, the government’s own research concludes this is not the case. If you are willing to accept these non-peer reviewed studies, then you may merely conclude that a poor performance correlates to a blood alcohol concentration above a .08. Moreover, the tests were previously used to show a blood alcohol concentration above a .10. Then the law changed in several jurisdictions and somehow it also changed scientific results.

Consequently, if you believe NHTSA’s own research, these agility tests do not show impairment. There merely make it appear to show impairment. 

A Person Accused Of DUI Deserves A True Second Opinion - Mon, 15 Jun 2009 18:08:27 -0700

Arizona DUI cases almost always involve a chemical test. There is a movement in Arizona towards the exclusive use of blood testing. It is well settled that blood testing is more accurate than breath testing. But how accurate is blood testing? Can it truly determine a person's blood alcohol concentration? I believe that these are reasonable questions to be asked by a person accused of DUI and facing 30 to 45 days in jail.

Under our system of justice we should demand better answers from the government than "because we said so" or "because our lab has the highest standards." Simple conclusions are not good enough in science and they should not be good enough in justice.

So who checks the government's test results in Arizona? The simple answer is the government. They merely claim to check themselves. I have yet to see one Arizona crime lab that conducts blind testing by an independent party.

Here is how the actual process works. In Arizona DUI cases, The government expert will tell juries that they do double check their work. That is, they have a quality assurance program to make sure the blood alcohol test results are accurate. But the government's oversight of their work is not what you my think. Instead retesting every sample, or randomly retesting a portion of the samples, the lab merely does a technical review.

A "technical review" is not retesting. The Government toxicologist usually puts between 30 to 40 blood samples into a blood tester. Then they turn the blood tester on and leave. The blood tester commonly runs overnight and the printed results are reviewed by the government lab person.

 

This review of the printed documents is what is known as a technical review. The actual documents are called chromatograms. They are simply pieces of paper with graphs and data on them (retention times, area counts, etc...) If the run has the usual 30 to 40 samples there could be well over 100 pages of data.

In court, the government will tell the jury that they "double check" all the tests. What they actually do is take those 80 to 100 pieces of paper and give it to another employee of the same lab.  That person then reviews the data. As long as the data appears to be consistent, they conclude it is an accurate test. In Court, they tell the jury they got a second opinon from another analyst to ensure the accuaracy of the tests.  

A nationally recognized expert, Dr. A.W. Jones, has opined that in forensic testing of blood samples retesting should be done, not a mere a "technical review." It is his opinion, that a mere technical review is inadequate to ensure the accuracy of the test results.

This standard makes perfect sense in DUI cases because the level of punishment is often dependent upon the test result. If a person's blood alcohol concentration result is .165 the person is facing a minimum of 30 days in jail. If he was under a .150 then he is merely facing 1 day in jail. Is it too much to ask the government to check their work when 29 days of jail is at stake? I guess the answer depends on how important the result is to you.

If you were at the doctor and she said "the blood tests were back," "we need to operate," let's "prep for the mastectomy." Most people would seek a second opinion. Why...because the issue is too important to merely rely on the first test. When it matter to you - you retest.

P.S. I will address the Defendant's ability to do their own retesting in my next entry.

 

A Well Written Post on The Source Code Issue - Mon, 26 Jan 2009 20:44:46 -0700

I ran across an excellent post discussing the source code issue.  That is, the fight between criminal defense attorneys and the maker of the breath tester (CMI) to disclose the code used in their breath testers.  CMI will not allow an inspection of the code.  Consequently, it cannot be checked for accuracy.  CMI essentially tells everyone charged with DUI to "just trust us."

Ed Brayton, a journalist and the co-founder of Michigan Citizens for Science, discusses the source code litigation in Florida.

Here's a very interesting case from Florida, where an appeals court has upheld a lower court ruling that threw out evidence from a breathalyzer test in a drunk driving case because the manufacturer of the device refused to release the source code and allow defense experts to analyze the accuracy of the machines.

The results of breath tests in more than 100 local drunken-driving cases will not be allowed at trial, a judge announced Tuesday.

The validity of those breathalyzer tests has been challenged for more than three years because of the Intoxilyzer 5000, a machine that uses a breath sample to measure a person's blood-alcohol content.

Manatee County Judge Doug Henderson ruled two years ago that any Intoxilyzer 5000 tests were inadmissible in trial, but prosecutors appealed. On Tuesday, Henderson told lawyers that his ruling had been affirmed by the Second District Court of Appeal and Circuit Court.

Breath analysis machines are notoriously inaccurate and this has been a problem for a very long time. Dr. David Hanson, a sociologist who has written on this issue for decades, writes:

Breath analyzers (Breathalyzer, Intoxilyzer, Alcosensor, Alcoscan and BAC Datamaster are common brand names) don't actually test blood alcohol concentration (BAC), which requires the analysis of a blood sample. Instead, they estimate BAC indirectly. Different types of machine use different techniqes and larger machines generally yield better estimates than do hand-held models. Therefore, some states don't permit data or "readings" from hand-held machines to be presented as evidence in court. South Dakota does not even permit evidence from any type or size breath tester but relies entirely on blood tests to ensure accuracy and protect the innocent.

A major problem with some machines is that they not only identify the ethyl alcohol (or ethanol) found in alcohol beverages, but also other substances similar in molecular structure. Those machines identify any compound containing the methyl group structure. Over one hundred compounds can be found in the human breath at any one time and 70 to 80 percent of them contain methyl group structure and will be incorrectly detected as ethyl alcohol. Important is the fact that the more different ethyl group substances the machine detects, the higher will be the false BAC estimate.

The National Highway Traffic Safety Administration (NHTSA) has found that dieters and diabetics can have acetone levels hundreds and even thousand of times higher than that in others. Acetone is one of the many substances that can be falsely identified as ethyl alcohol by some breath machines.

One investigator has reported that alcohol-free subjects can generate BAC readings of about .05 after eating various types of bread products.

Substances in the environment can also lead to false BAC readings. For example, an alcohol-free subject was asked to apply a pint of contact cement to a piece of plywood and then to apply a gallon of oil-base paint to a wall. The total activity lasted about an hour. Twenty minutes later the subject was tested on an Intoxilyzer, which registered a BAC of .12 percent. This level is 50% higher than a BAC of .08, which constitutes legal intoxication in many states.

Similarly, a painter with a protective mask spray painted a room for 20 minutes. Although a blood test showed no alcohol, an Intoxilyzer falsely reported his BAC as .075.

Any number of other products found in the environment can cause erroneous BAC results. These include compounds found in lacquers, paint removers, celluloid, gasoline, and cleaning fluids.

Other common things that can cause false BAC levels are alcohol, blood or vomit in the subject's mouth, electrical interference from cell phones and police radios, tobacco smoke, dirt, and moisture.

Breath testers can be very sensitive to temperature and will give false reasings if not adjusted or recalibrated to account for ambient or surrounding air temperatures. The temperature of the subject is also very important. Each one degree of body temperature above normal will cause a substantial elevation (about 8%) in apparent BAC.

Many breath testing machines asume a 2,100-to-1 ratio in converting alcohol in the breath to estimates of alcohol in the blood. However, this ratio varies from 1,900 to 2,400 among people and also within a person over time. This variation will lead to false BAC readings.

Physical activity and hyperventilation can lower apparent BAC levels. One study found that the BAC readings of subjects decreased 11 to 14% after running up one flight of stairs and 22-25% after doing so twice. Another study found a 15% decrease in BAC readings after vigorous exercise or hyperventilaion.

Some breath analysis machinnes assume a hematocrit (cell volume of blood) of 47%. However, hematocrit values range from 42 to 52% in men and from 37 to 47% in women. A person with a lower hematocrit will have a falsely high BAC reading.

It's about time a judge took a stand on this issue.

I Need to Hire the Guy that Made This Video. - Sat, 03 Jan 2009 06:01:47 -0700

Here is a very well researched and produced video regarding an Ohio DUI case.  While I do not agree with everything he argues, her certainly makes some vaild points.  Enjoy:

 

Please Think About This Before You Drink And Drive This Holiday Season - Sat, 20 Dec 2008 10:14:56 -0700

There is significantly more drinking and driving during the holidays.  It happens every year, in every place.  I have plenty of business.  However, I don't want you to become a customer. Trust me, you have better things to do than hang out with me in a courtroom for the next three or four months.  Thus, I am going to republish a post that I have previously written.  The post is titled: "3 Things I Wish People Knew Before Drinking & Driving."

Before you read the post, please watch this video.  The story is more persuasive than anything I could ever write.

 

 

This post was originally published on 07/31/08:

It's 5:00 p.m. on Friday afternoon in Phoenix, and Joe just walked through the door of his favorite restaurant to meet some friends for happy hour.  He drove himself to the restaurant.  When he is done, he is going to drive to his house in Scottsdale.

At the table, Joe sees everyone has one of the restaurant's signature margaritas in front of them.  The waiter comes to the table and asks Joe: "can I get you something to drink?"  Before Joe answers this question, I wish he would consider the following facts:

1. There is no crime of Drunk Driving in Arizona.  Arizona law makes it illegal to drive while Joe is impaired to at least the slightest degree by alcohol.  This means that if Joe's ability to drive is impaired to any degree, Joe is technically in violation of the law;
2. If Joe is stopped by the police, they will stick a needle in Joe's arm.  Regardless of the law on this subject, it has been my experience that if Joe is stopped by a police officer for a traffic violation, and the officer smells any alcohol, Joe is going to end up taking a chemical test.  Many police agencies are now using blood testing instead of breath testing.  If the officer smells alcohol on Joe's breath (or just imagines it), Joe is going to have a needle stuck in his arm and a blood sample will be taken.  The results of the blood test will probably take at least 30 days to come back.  While Joe is waiting to find out the results of the blood test, he will not sleep very much or very well;
3. If Joe refuses the blood test, the officer will get a warrant and forcibly take his blood.  Once the officer meets the requirements of Arizona's implied consent law, he may require Joe to submit to a chemical test.  If Joe says "no," he will then lose his driver's license for 12 months.  Moreover, the officer will then make a phone call to the judge.  Within minutes, the judge can then issue a telephonic warrant.  If Joe still refuses, he will be held down by several police officers, and a needle will be shoved into his vein. 

Now if Joe knew these three things when the waiter asked him: "can I get you something to drink" - how might Joe answer?  I think the average Joe would say: "Yes...Diet Coke."

Please consider the above before you drink and drive.  Moreover, if you know someone who needs to become aware of these "3 Things" please use the "email this post" button at the bottom and send it to them.  This is a subtle way of possibly preventing a life changing tragedy. Thanks!