Challenging Blood Tests

Why Experience Matters: Challenging Blood Tests

There are plenty of DUI attorneys out there. Each one has a different level of experience and a different way of handling cases. Some attorneys try to simply negotiate a plea in every case. We are not that firm.

At Bowser Law, we pride ourselves on fighting for the citizens accused of a crime. We take cases to trial to fight for the best possible result for our clients. When you decide to fight, experience matters. Attorney Bowser’s results prove his success.

In this blog series, we will detail some examples of how experience makes a difference in DWI/OUI cases. Previously in this series, we have covered:

Today we will look at Challenging Blood Tests.

Many drivers think that a bad blood test result is an automatic conviction. This is simply not true. There are many ways to challenge a blood test result and this is why you should choose an attorney who has real experience with forensic science. Attorney Mike Bowser has not only attended training seminars on blood testing, he has also completed laboratory courses taught by scientists. He uses this extensive knowledge to protect his clients.

There are many common issues which could produce an unreliable blood test result. For example:

Bad Lab Technicians

Blood tests are conducted by humans who must follow specific scientific procedures. However, since many state crime labs are horribly under-staffed, technicians resort to taking shortcuts to keep up with their workload. In some cases, results are submitted without any testing at all.

Take the case of Annie Dookhan. She was a technician at the William A. Hinton State Laboratory Institute in Boston who admitted to tampering with evidence and forging test results.

Her main motivation was to keep up with the flood of incoming cases. So instead of taking the time to properly test the samples, she made up readings without any testing at all. As a result, more than 20,000 convictions were dropped because her evidence could not be trusted.

Contamination of Samples

There are very specific guidelines for handling blood samples which police and crime labs must follow to ensure the integrity of the samples. Deviating from those protocols can result in contamination. Here are some questions that need to be asked:

  • Is there a clear chain of custody?
  • Were the procedures documented correctly?
  • Were the tubes transported under the correct protocols?
  • Were the samples stored under the proper temperature?
  • Were the tubes shaken properly by the technician?

If these procedures were not followed correctly, this may be grounds to challenge the results of the blood test.


Testing equipment and instruments need to be maintained to ensure they are working properly. Part of that maintenance is making sure the machines are calibrated correctly. This calibration needs to be done as per a predefined schedule which needs to be documented. If the equipment was not calibrated correctly, it could cause the results to be compromised. Just think of the old analog bathroom scales. If the dial is not set to zero, the end result will not be reliable.


Even if the testing was done correctly, it has no scientific standing if the procedures were not correctly documented. Without proper documentation, the evidence would be based on “an act of trust”. This is against scientific and legal standards.

Attorney Mike Bowser has extensively studied the forensic science behind blood testing and uses that knowledge to protect his clients. He goes the extra mile to search for scientific and procedural issues that can be raised in court. If you have a DUI case and can’t afford to be convicted, call Attorney Mike Bowser at (888) 414-9202 today for your free case consultation.