When a police officer sees you swerving or notices other signs that they think indicate driving while intoxicated (DWI), they will turn on their lights and pull you over. From the moment they first approach your vehicle, they are on the hunt for evidence that can allow them to arrest you and charge you with a DWI offense.

They will look through the windows of your car to see if they can spot any open intoxicants or other signs of illegal activity. When you roll down your window, they will immediately try to detect the scent of alcohol on your breath and any signs of impairment in your face, such as a red nose or flushed cheeks.

What steps will they take to establish the grounds to arrest you for a DWI?

They will ask you specific questions

The police officer who pulled you over will want to know where you are going and what you were doing before. They may also inquire about whether you have had anything to drink. If you answer affirmatively, they will then want details about how much you have had to drink.

Even if you tell them honestly that you have only had one or two beers, they will likely be suspicious and at that point, they will ask you to exit the vehicle. If you deny having anything to drink but they know what they think are signs of alcohol in your behavior, they will likely ask you to exit the vehicle then as well.

They will ask you to perform field sobriety tests

There is plenty of medical science looking into how alcohol affects the human body. Police officers have training about those bodily responses to chemical intoxicants. They use this information by having you perform certain standardized field sobriety tests.

Having you walk in a straight line and then turn and walk back, balance on one foot and follow their finger with your eyes can help them screen for signs that someone has likely consumed an intoxicating amount of alcohol. Performance on someone’s field sobriety test may give that officer the probable cause they need to ask a driver to perform a chemical test.

They will collect chemical evidence

When your words or behavior make an officer believe that you’ve had too much to drink, they may have probable cause to request a chemical breath test. Depending on how you perform on that test, they may arrest you right there on the side of the road. The information gathered from your conversation, the field sobriety test and the chemical breath test will all become evidence in the criminal case against you.

Learning about how the state gathers evidence of a DWI offense can prepare you to fight back against those charges.