Can You Challenge OUI Evidence in Maine? Yes, Here’s how
Many people arrested for Operating Under the Influence (OUI) in Maine assume they have no choice but to plead guilty. That assumption is often wrong. OUI cases in Maine frequently rest on evidence that is far less reliable than prosecutors make it appear, and an experienced defense attorney knows exactly where to look for weaknesses.
Attorney William T. Bly of The Maine Criminal Defense Group holds certifications that are rare outside of law enforcement: he is a certified breath alcohol technician and a certified instructor of standardized field sobriety testing. That means when he reviews the evidence in your case, he is evaluating it with the same technical knowledge used to collect it. Few defense attorneys in Maine can say the same.
The cornerstone of most OUI prosecutions is sobriety test results, whether chemical tests like breathalyzers or blood tests, or field sobriety assessments conducted roadside. Both forms of testing are subject to human error, faulty equipment, and improper administration. This matters most when your blood alcohol content (BAC) is only slightly above the legal limit of 0.08%. In those cases, even a small testing error can be enough to cast doubt on the entire prosecution.
Understanding the types of evidence used in Maine OUI cases, and how each can be challenged, is the first step toward building a strong OUI defense.
Chemical vs. Field Sobriety Tests in Maine
Maine law enforcement relies on two primary types of sobriety tests to build OUI cases: chemical tests and field sobriety tests. Each has its own procedures and its own vulnerabilities.
Chemical Sobriety Tests (BAC Testing)
Chemical tests measure blood alcohol content. If your BAC registers at 0.08% or higher, you can be charged with OUI under Maine law. Officers typically use breath tests administered via:
- breathalyzer,
- blood tests, or
- urine tests
Although these tests are presented as scientific, they are not infallible. Improper calibration, contaminated samples, undiagnosed medical conditions, and operator error can all produce false or inflated results. When a BAC reading is only marginally over the limit, the margin for error in the testing process becomes directly relevant to your defense.
Field Sobriety Tests (FSTs)
Field sobriety tests are physical and cognitive assessments conducted during a traffic stop. The three standardized tests used in Maine are:
- the horizontal gaze nystagmus (HGN) test,
- the walk-and-turn, and
- the one-leg stand.
These tests are inherently subjective. They depend on the officer’s interpretation of your performance, and external factors including poor lighting, uneven pavement, medical conditions, nervousness, and footwear can all affect results. A person can fail a field sobriety test without being impaired.
How to Challenge OUI Evidence in Maine
Was the Traffic Stop Legal?
Before any test results can be challenged, it is worth examining whether the traffic stop itself was lawful. Under the Fourth Amendment, an officer must have reasonable suspicion of a traffic violation or criminal activity before pulling a driver over. If that standard was not met, any evidence collected during the stop, including BAC results and field sobriety observations, may be subject to suppression.
This is often the most consequential challenge available in an OUI case, and it is one that gets overlooked when defendants don’t have experienced legal counsel.
Challenging a Blood Tests
Blood testing is generally considered more accurate than breath testing, but it is also more susceptible to procedural errors that can compromise results. A blood sample must be properly labeled, stored, and transported from the point of collection to the laboratory. Any break in that chain of custody creates a legitimate basis for challenging the reliability of the results.
Additionally, because alcohol continues to be absorbed into the bloodstream after a person stops drinking, there are situations where a driver’s BAC at the time of the test was higher than it was while they were actually operating the vehicle. This is known as the rising BAC defense, and it is particularly relevant when there was a significant delay between the traffic stop and when the blood sample was drawn.
Challenging a Breath Test
Breath testing in Maine is governed by strict requirements. The equipment must be approved by the Maine Department of Health and Human Services, and the test must be administered by a certified operator following established protocols. When either of those conditions is not met, the results can be challenged.
Common grounds for challenging a breath test include improper calibration of the device, failure by the officer to follow proper administration procedures, equipment that has not been serviced or certified within required intervals, and interference from other compounds that some breathalyzer sensors can mistake for alcohol. Attorney Bly’s certification as a breath alcohol technician means he can review the actual calibration records, maintenance logs, and administration procedures in your case and identify errors that a less specialized attorney might miss.
Challenging a Field Sobriety Test
Standardized field sobriety tests must be administered according to specific protocols established by the National Highway Traffic Safety Administration (NHTSA). Officers are required to be trained and certified in their administration. When those protocols are not followed precisely, the validity of the results can be questioned in court.
Grounds for challenging field sobriety test results include
- the officer failing to give clear instructions,
- administering the test on an uneven or poorly lit surface,
- failing to account for the driver’s physical condition or medical history, and
- the officer lacking proper certification to administer the test.
Attorney William Bly’s certification as a field sobriety testing instructor gives him direct insight into where officer errors occur and how to document them effectively.
Officer Certification and Equipment Approval
Two Maine-specific issues deserve attention on their own.
First, breath testing in Maine must be conducted by personnel certified by DHHS. If the administering officer was not properly certified at the time of your test, that is grounds to challenge the admissibility of the results.
Second, the device used must appear on the DHHS-approved equipment list. Testing performed on unapproved equipment does not meet the legal standard required for the results to be admitted as evidence.
Why the Evidence in Your Maine OUI Case Deserves Scrutiny
OUI prosecutions in Maine often appear straightforward on paper. There is a BAC number, there is an officer’s report, and there may be field sobriety observations. But each of those pieces of evidence was produced by a process, and every process has the potential for error.
The difference between a conviction and a dismissal often comes down to whether someone with the right knowledge reviewed that evidence carefully. Attorney William T. Bly has spent decades focusing on OUI defense in Maine. His technical certifications, courtroom experience, and knowledge of Maine OUI laws give him the tools to find the issues that matter and argue them effectively.
If you have been charged with an OUI in Maine, The Maine Criminal Defense Group can help you. Call us now or contact us directly online.
Challenge OUI Frequently Asked Questions
Can OUI evidence be suppressed in Maine?
Yes. If evidence was obtained through an unlawful traffic stop, collected using improperly calibrated equipment, or gathered by an officer who was not certified to administer the test, your attorney can file a motion to suppress. If the court grants that motion, the affected evidence cannot be used against you, which can significantly weaken or end the prosecution’s case.
What makes a breathalyzer result invalid in Maine?
Several factors can invalidate a breath test result in Maine, including use of equipment that is not on the DHHS-approved list, administration by an uncertified officer, failure to follow required testing protocols, improper calibration or maintenance of the device, and interference from other compounds detected by the sensor. Any of these issues can form the basis of a legal challenge.
Can a field sobriety test be challenged in court?
Yes. Field sobriety tests must be administered according to NHTSA standards by a properly trained and certified officer. If the instructions were unclear, the conditions were unsuitable, the officer was not certified, or the driver’s physical condition was not taken into account, the results can be challenged as unreliable.
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