Breathalyzer Tests

Our Ann Arbor Drunk Driving Law Firm is Prepared to Challenge the Results of Your Breath Test

Police office holds breathalyzer

When arrested for a DUI, you may be asked to take a breath test. This test will be used to determine your blood alcohol level, and then used against you in a prosecution. The breath test, often called a Breathalyzer, has many flaws and our Ann Arbor drunk driving law firm is ready to help you fight your DUI charges.

What is a Breath Test in Michigan?

After an arrest for a DUI, a police officer will ask you to take one of two tests. There are breath tests and blood tests. A breath test only tests for alcohol while a blood test can theoretically test for any drug in addition to alcohol.

Breath testing in Michigan is done on a machine called the DataMaster DMT. Most police agencies will have their own machine. When a person is arrested by a Michigan State Police trooper, that person will generally give a blood test. This is because the MSP patrol everywhere and don’t have a breath test machine back at their own station to use.

A person arrested for suspicion of a DUI gets taken back to the police station. Then the officer must watch the person for at least 15 minutes to ensure the person does not vomit, burp, or eat anything. Then the person blows into a tube connected to the machine. The officer will have the machine take two readings of blood alcohol content.

Breath Testing v. Blood Test to Find Your BAC

There are two main methods for testing for blood alcohol levels. There is the breath test and a blood test. (There’s also a urine test, but those are not really done).

The blood test is more accurate than the blood test. There is a simple reason why. A blood test directly tests for blood alcohol content. The test is testing the blood. A breath test does not directly test the blood. The machine gets an intake of gas from a person, and from that gas tries to determine what the blood alcohol content would be from analyzing the gas. Therefore, the analysis is an estimate of the blood alcohol content, and not a direct measure.

Why would a police officer have you take a breath test when a blood test is more accurate? Because it’s cheaper and easier for the police.

Defective or Malfunctioning Breath Test Machines

Prosecutors and police officers tout the results of these machines as if they are perfect. The reality is no machine is perfect. Has your computer ever frozen and had to restart? Has your “smart” phone ever done something you didn’t want it to do? How can a prosecutor say this machine gave a perfect result when we know machines aren’t perfect. Our daily reality tells us that machine are not perfect.

These machines malfunction just like any machine. There is nothing extraordinary about them. Many people see the machine produce a number and we are trained in our world to respect that number without question.

Breathalyzers do not produce a 100% accurate reading – they produce an “estimate” of blood alcohol content. The machine cannot tell us that exact amount of blood alcohol content, only an estimate. This is because, after all, the machine does not test the blood but rather a person’s breath. The machine estimates the blood alcohol content from a measurement of breath and converts that measurement into an estimate of what blood alcohol content could be.

A good DUI defense lawyer knows that these machines are unreliable and does not simply respect the result given by the machine in a breath test.

Can an Ann Arbor Drunk Driving Law Firm Challenge the Breathalyzer Results?

In short…absolutely.

There are many ways to challenge the results of a breath test. The test must be performed in the right way. A test given the wrong way cases doubt on the reliability of the result. In many cases there is a video of the breath test. We can see whether the officer gave the test the right way.

In addition, the machines must be serviced on a regular basis. As we saw in the 2020 DataMaster DMT Scandal, this doesn’t always happen.

Michigan’s DataMaster DMT Scandal

In January 2020, the Michigan State Police announced there was fraud by the people whose job it is to service the machines. The MSP acknowledged the fraud affected at least ten machines or so. However, the MSP is not being open and transparent in telling the public exactly what the fraud was. This is one (though a big one) example of they the machines shouldn’t be trusted. The machine technicians are required to service the machines at least once every 120 days, and one theory is this may not have been completed by the technicians. ArborYpsi stays on top of the developments.

Our Lawyers are Prepared to Fight Your BAC in Court

In a drunk driving breath test case that goes to trial, there will be too witnesses for the prosecution that will talk about the breath test. The first is the arresting officer. The arresting officer will describe the procedures of the test and the results. The second officer is called the keeper of the logs. The keeper of the log’s role is to testify that the machine were regularly serviced at least once every 120 days and that the machine’s weekly self-test occurred during the week before the defendant’s breath test.

Both of these officers will undoubtedly testify that these machines are the greatest things ever invented and more advanced than a super computer. The officers will have no doubt the test results from the breath machine are accurate. This is far from the truth.

At trial it is necessary to fight this myth. Without challenging these numbers the jury will believe the officers. At ArborYpsi Law, we are prepared and willing to call the officers on this assumption so the jury sees the truth about these breath machines.

Don’t Trust the Machine: Fight Your Breathalyzer Results With Our Ann Arbor Drunk Driving Law Firm

We know that machines aren’t perfect. We also know that the result of the breath test will be used against you in court. A good DUI defense attorney knows that these machines are unreliable and uses that fact to the client’s advantage.

In a lot of ways, DUI defense begins with the understanding that we shouldn’t trust the machines. DUI defense all begins with a lack of respect for the machine. Beware of an attorney who tells you there’s nothing to be done in your case because the machine said your BAC was over .08. Sam Bernstein is an attorney specializing in DUI defense, and our Ann Arbor drunk driving law firm is here to fight your rights.

Call ArborYpsi Law at (734) 883-9584 or by e-mail at

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