DWI investigations routinely start at checkpoints, accidents, and traffic stops.  Each of these types of DWI investigations start in different ways, but they often end the same way.  Lets look at how each of these begin.

DWI Checkpoint

Most people have encountered DWI checkpoints before.  Imagine you are heading home from a party, where you enjoyed a couple of drinks with your friends.  Traffic begins backing up.  As you come around the corner, you see flashing lights and police cars everywhere.  You don’t think you should have any problem- after all you have only had a couple of drinks.  You pull up to the checkpoint- “License and registration please,” the police officer asks.  Even though you don’t feel like you have done anything wrong, your hands shake a little as your retrieve your information.  Next thing you know, you are out on the side of the road under investigtion.

Traffic Accident

After enjoying a meal and a few drinks at a restaurant, you are driving home, when suddenly a deer runs out in front of your vehicle.  Shocked, you slam on the brakes and swerve to avoid hitting the deer.  After you miss the deer, you spin and find yourself off of the road.  Someone sees the incident and calls 911.  The police arrive and an investigation begins before you know it. After talking to the officer a minute, he or she says that there are some tests that he or she wants you to try.  Your anxiety level skyrockets as you find out you are under investigation for DWI.

Traffic Stops

After relaxing at the bar for a few hours, you head home.  An officer stops you for some traffic violation.  After pulling over, you wait for the officer to come to discuss the reason that he or she pulled you over.  Maybe you are nervous, knowing that the smell of alcohol is on your breath, or maybe you know that you are not impaired, so you are not worried.  However, once the officer smells “the odor of an alcoholic beverage” on your breath, then you are immediately the subject of a DWI investigation.

Standardized Field Sobriety Tests

At this point, the DWI investigation follows a familiar pattern.  Typically, the officer will ask you to follow some stimulus, like the tip of a pen, with your eyes.  What the officer is checking for is Horizontal Gaze Nystagmus.  This is an involuntary jerking of the eye that is a physiological response to impairment.

After this test, the officer moves on to the one leg stand test.  During this test, the officer will ask you to raise one of your legs off of the ground about 6 inches, look at your foot, and to count “one thousand one, one thousand two…” or “one thousand and one, one thousand and two” for as long as the officer asks you too.  During this time period, you are instructed to keep your hands down at your side, and that you should try to keep your foot from touching the ground.  If your foot touches the ground, you are instructed to keep trying.

The final test that is typically used in a DWI investigation is the walk and turn test.  During this test, you will be requested to “walk the line.”  You will be instructed to put one foot in front of the other, and to count your steps.  At the end of those steps, you are to turn, using small steps, and walk back the same way that you came, counting as you go.  On each of these three types of Standardized Field Sobriety Tests (SFST), there are a specific number of “clues” that officers watch for.  Each SFST requires a certain number of clues for you to fail the test.

Non-Standardized Tests

Though not common, officers sometimes use other tests.  One example is the alphabet test, in which the officer will require you to start with one letter mid way through the alphabet and end on another letter midway through the alphabet, without singing.  Another common test is the counting test, in which you are asked to begin counting from a certain number, backwards down to a different number.  For instance, the officer may ask you to count from 57 to 34.  Finally, the officer may administer the finger count test, in which you are required to touch your fingers to your thumb in order while counting out loud.

Needless to say, even a sober person could score poorly on these tests if they are nervous enough.  After administering these tests, the officer will ask you blow into a portable breath test.  The officer should determine if you had a drink in the past 15 minutes, because it could skew the test.  After you blow into the portable breath test once, it will return a reading.  The officer will ask you to blow a second time as well.  These readings are not admissible to show your blood alcohol level.  However, they do indicate whether you are positive or negative for alcohol.

Intox EC/IR II

If the officer thinks that you are impaired, he or she will take you to have your breath tested by an Intoxilyzer machine.  This is the machine that “counts,” meaning that the blood alcohol concentration shown in this test is admissible in court.  The officer takes two samples.  The lower of the two readings is admissible against you in court.


The process of DWI investigation may seem very complex, but we deal with this on a daily basis.  If there is video of your stop then we will be able to review your tests.  Our DWI lawyer will work hard to help you with your case, and help you understand what you are facing.