What to Do If You’re Stopped at a DWI Checkpoint in O’Fallon
DWI checkpoints, also called sobriety checkpoints, are legal in Missouri. They must be clearly marked, publicly announced in advance, and carried out in a neutral and minimally intrusive manner.
Even though DWI checkpoints are legal, what you do and say matters. You have the right to remain silent, the right to refuse certain tests, and the right to challenge how the checkpoint was conducted. Here’s what to expect and how to handle a checkpoint stop.
What Happens During a DWI Checkpoint Stop
When you pull up to a checkpoint, an officer will ask for your driver’s license, registration, and proof of insurance. The officer may also ask you a few brief questions, like where you’re coming from or whether you’ve had anything to drink.
You are required to provide your license and vehicle documents – but you are not required to answer questions about where you’ve been, what you’ve had to drink, or anything else that could incriminate you. Politely declining to answer is legal and often the wisest choice.
If the officer sees signs of impairment, they may ask you to pull over for further screening. This could include field sobriety tests or a portable breath test.
Can You Turn Around to Avoid a Checkpoint?
You can evade a stop, but only if it’s legal and safe to do so. Law enforcement can monitor vehicles that turn away before reaching a checkpoint. If you make an illegal turn or violate traffic laws to avoid the stop, that could give the police enough reasonable suspicion to pull you over.
Even legally trying to avoid a checkpoint can attract police attention. Officers may follow you or conduct a separate traffic stop based on your behavior.
Should You Submit to Field Sobriety or Breath Tests?
Missouri’s implied consent law means that refusing a chemical test (a breath, blood, or urine test) after a lawful DWI arrest can lead to a one-year license revocation.
Field sobriety tests and preliminary breath tests (PBTs) are different. You are not legally required to take field sobriety tests or a PBT during the initial stop. These tests are voluntary and can be subjective, even when properly administered. Politely declining to take the tests can limit the evidence that officers gather against you.
Fourth Amendment Defenses at DWI Checkpoints
Even though DWI checkpoints are legal in Missouri, they must follow strict rules. The Fourth Amendment protects you from unreasonable searches and seizures. That usually means police need a warrant or at least reasonable suspicion to stop you. DWI checkpoints are an exception.
To comply with the Fourth Amendment, there are legal guidelines designed to limit arbitrary stops. For example:
- Brief, Limited Stops – Officers can check your license and insurance, but they can’t detain you without clear signs of impairment.
- Public Advance Notice – Checkpoints must be announced ahead of time, either through news outlets or law enforcement channels.
- Neutral Stopping Pattern – Officers must stop cars using a set formula (like every third car), not their personal, subjective judgment.
- Written Procedures – The checkpoint must follow a plan approved by supervising officers. It can’t be made up in the moment.
- Visible, Marked Location – The site should have signs, lights, and uniformed officers to show it’s an official operation.
If officers don’t follow these rules, the stop may violate the Fourth Amendment. Any evidence they collect could be excluded from your case. You may also have a defense based on how the officer conducted the stop. If you were detained longer than necessary or questioned aggressively without cause, that could support a Fourth Amendment challenge. A DWI checkpoint defense lawyer can investigate and raise any violations as part of your defense.
Talk to a DWI Checkpoint Defense Lawyer in O’Fallon
If you were stopped or arrested at a sobriety checkpoint in O’Fallon, contact The O’Rourke Law Firm to discuss your next steps.