Top Police Mistakes in a DUI Investigation

If you have been arrested and charged for a drunk driving offense, you might think that you will automatically be found guilty as charged. Even if you were impaired, the prosecutor is still required to meet the burden of proof to prove your guilt beyond a reasonable doubt. Police officers sometimes make mistakes that can lead to a dismissal of your charges or a not guilty verdict at trial.

At DiCindio Law, we can review your case to determine whether the officer made mistakes that can be explored. Here are some of the most common mistakes that officers make in DUI cases.

Making an invalid stop

Police officers cannot stop cars unless they have reasonable suspicion to believe that the occupants have committed traffic violations or crimes. A stop cannot be based on the officer’s hunch without anything to support the basis for it.

Typical examples of the types of things that could support a stop include traffic offenses or equipment violations. If the officer stopped you for an invalid reason, the stop can be suppressed. When a stop is found to be invalid, everything that the officer learns after the stop will also be suppressed. In a DUI case, this would include the officer’s observations of you, your performance on any SFSTs, your arrest, and the results of your chemical testing. When a stop is suppressed, it normally means that the prosecutor will be forced to dismiss the charges.

Improperly administered field sobriety tests

Three field sobriety tests, including the one-legged stand, the walk-and-turn, and the horizontal gaze nystagmus tests, have been standardized by the National Highway Traffic Safety Administration. When these tests are properly administered, they can indicate that a driver is under the influence of alcohol. Officers must undergo training on how to properly administer the tests. Despite this, many DUI stops involve mistakes made during the administration of the SFSTs. Your lawyer can review the tests and challenge any mistakes that the officer made. This can result in the tests being suppressed from the evidence, which can weaken the prosecutor’s case.

Mistakes made during the chemical testing

Chemical tests in Pennsylvania can include a breath test, a blood test, or a urine test. Most officers choose the breath or blood test. Breathalyzer machines can give inaccurate results if they are not calibrated correctly and maintained regularly. The officer who administers the test must also follow specific procedures and have current certifications. If any mistakes have been made, they can make the results suspect. If your lawyer can demonstrate that the breathalyzer test was improperly administered, your results might be thrown out.

Blood tests are also subject to errors. Your lawyer might review the training of the person who drew your blood to make sure that the protocols were correctly followed. He or she might also review how the sample was stored and sent to the lab. Finally, your attorney might ask for the second vial of blood to be tested if he or she suspects that your sample might have been stored incorrectly or contaminated.

Lack of objectivity

Officers are expected to be fair and impartial when they pull people over. Part of this expectation includes making fair observations and being willing to admit when someone passed the standardized field sobriety tests. When an officer is not objective, videotape evidence often exposes the inconsistencies and inaccuracies in their reports.

Failing to document everything

Some police officers fail to save their field notes. These officers might subsequently claim that the people they stopped acted in a specific way or failed a field sobriety test. When an officer who fails to properly document everything is asked to support his or her conclusions and report, it is common for the officer to claim that he or she does not remember or to rely on a summary that he or she created from memory.

Officers should never destroy field notes until after a case has been completed.

Assuming that the DUI case cannot be lost

A common mistake that police officers make is believing that their DUI cases cannot be lost. When officers make this mistake, they are likelier to make other errors in their testimony and their courtroom demeanor. Officers who are overconfident in their abilities to sway juries and judges are often unprepared. This can leave them open to a vigorous cross-examination and an exposure of their mistakes.

Ignoring the rights of the defendant

The criminal justice system recognizes the constitutional rights of defendants. Charges are not evidence of guilt, and people have numerous rights against unfair prosecutions. Some police officers treat the criminal justice system as a game and look at defendants as nothing but pawns. These officers tend to ignore the rights of defendants and may be disrespectful to the suspects, witnesses, jury, lawyer, and prosecutor. An officer who behaves in this way only serves to harm his or her case. If he or she has violated the defendant’s constitutional rights, the officer runs the risk that the entire case will be thrown out. Disrespectful officers also tend to harm the state’s case when they behave poorly in the courtroom.

While police officer mistakes can make your DUI stop and subsequent case emotionally difficult, they can be potentially helpful in securing an outright dismissal or a plea to a lesser offense.

Contact Our DUI Law Firm in West Chester, PA

If you are facing criminal charges and need legal help, contact the West Chester, PA DUI lawyers at DiCindioLaw, LLC to schedule a free initial consultation.

DiCindio Law, LLC

29 S Walnut St
West Chester, PA 19382
(610) 430-3535


***This blog article is made available by the law firm publisher for educational purposes and to provide general information, not to provide specific legal advice. By reading, you understand that there is no attorney client relationship between you and the publisher. The above listed information does not include the entire crimes code, annotations, amendments or any recent changes that may be relevant. The information provided is for informational purposes only and may not reflect the most current legal developments. These materials are not intended, and should not be taken, as legal advice on any particular set of facts or circumstances. Please contact DiCindio Law, LLC for a consultation and to discuss what law is relevant to your case. ***