Field Sobriety Tests in Colorado DUI Cases

Field sobriety tests are often used by police in Colorado to decide whether to arrest someone for DUI, but these tests are far from perfect. Weather conditions, poor lighting, uneven roads, medical issues, or even nervousness can all affect how a person performs, making the results unreliable. Despite this, officers frequently treat them as strong evidence of impairment. If you are facing DUI charges, it’s critical to understand both the limitations of these tests and how they may be challenged in court.

At DUI Law Firm Denver, we know how to expose the weaknesses in field sobriety test evidence and use our experience, legal knowledge, and aggressive defense strategies to protect your rights. Call us today for a confidential consultation and start building a defense that works for you.

Top-Notch Legal Representation from an Experienced DUI Defense Lawyer

If you’ve been arrested for DUI after taking a field sobriety test, you need more than just a lawyer; you need a defense team that knows how to expose the weaknesses in these tests. At DUI Law Firm Denver, we understand that field sobriety tests are not always reliable. Poor weather, uneven roads, medical conditions, fatigue, or even an officer’s lack of proper training can all lead to unfair results.

Our attorneys dig deep into the details of your case. We review the officer’s training and conduct, the testing conditions, and whether the required procedures were followed to the letter. We also examine whether health issues, medications, or other factors could have affected your performance.

By combining legal expertise with scientific insight, we challenge flawed evidence and fight to weaken the prosecution’s case against you. Our goal is simple: to protect your rights, question unreliable test results, and deliver the strongest possible defense.

When your freedom, license, and reputation are on the line, trust DUI Law Firm Denver to fight aggressively for your future.

Police officer conducting roadside sobriety test. - Field Sobriety Tests in Colorado DUI Cases

What Are Field Sobriety Tests?

Field sobriety tests are used in Colorado to check whether a driver may be impaired by alcohol or drugs. Officers rely on two categories of tests: standardized tests approved by the National Highway Traffic Safety Administration (NHTSA) and non-standardized tests, which vary by situation and are less reliable.

Standardized vs. Non-Standardized Tests

Standardized tests include the three NHTSA-approved exercises: the Horizontal Gaze Nystagmus (HGN), Walk-and-Turn (WAT), and One-Leg Stand (OLS). These are widely accepted in court because they have been researched and validated.

Non-standardized tests, such as reciting the alphabet, counting backward, or touching the nose, are not officially recognized. They are more subjective, less consistent, and often carry less weight in court.

Commonly Used Tests in Colorado DUI Stops

Colorado police most often use the three standardized field sobriety tests:

Horizontal Gaze Nystagmus (HGN): Examines eye movements for involuntary jerking when following an object side to side, which may indicate impairment.
Walk-and-Turn (WAT): Requires nine heel-to-toe steps in a straight line, a precise turn, and nine steps back. Officers look for balance issues, missteps, or starting too soon.
One-Leg Stand (OLS): Involves standing on one foot about six inches off the ground while counting out loud. Losing balance, hopping, or putting a foot down can signal impairment.

These tests are designed to measure coordination, balance, and focus—abilities often affected by alcohol or drugs.

How Accurate are Field Sobriety Tests?

Field sobriety tests are not always accurate. Even when police officers do them right, the tests can still be wrong. Different tests show different accuracy levels.

HGN Test (Horizontal Gaze Nystagmus Test): 77% accurate, 23% wrong results.
Walk & Turn Test: 68% accurate, 32% wrong results.
One-Leg Stand Test: 65% accurate, 35% wrong results.
All Three Tests Together: 82% accurate, 18% wrong results.
Non-Standard Tests: Less than 50% accurate, more than 50% wrong results.

Many things can affect these tests. Medical problems, age, weight, or physical issues can change the results.

Weather or bad roads can also make it hard to do the tests right. The police officer’s training and experience matter a lot, too.

Because of these issues, some courts want more proof than just these tests to decide if someone was driving under the influence.

Problems with Field Sobriety Tests

Field sobriety tests have problems that make them less reliable and accurate for checking if someone is impaired.

Some of the main issues include things like bad weather or rough roads. People taking the test might have physical or medical problems that affect their performance.

Also, police officers might not always give the same instructions or might do the tests differently each time. Because the results depend on what the officer sees, one officer might think a person is impaired while another might not.

Environmental Conditions

In Colorado, when police officers give field sobriety tests, things around you can change how well these tests work. Different conditions can make it hard for someone to do these tests right, which can make it look like they’re drunk when they might not be.

Common problems include:

Weather: Snow, rain, or strong winds can make it hard to keep your balance or see well.
Ground: Sloped roads, gravel, or broken pavement can make it tough to stand steady.
Lighting: Bad lighting can make it hard for both the person taking the test and the officer watching.
Temperature: Being too hot or cold can make someone shiver or sweat, which might seem like they’re drunk.

These conditions should be written down because they can help argue against the test results in court.

Physical or Medical Conditions

Many health problems can affect sobriety tests in Colorado, even if someone hasn’t been drinking. Conditions like arthritis, back pain, knee injuries, ear problems, and nerve issues can make it hard to balance or move well during these tests.

Getting older, being overweight, or taking certain medicines can also make test results unreliable. Diseases like diabetes can have symptoms that look like drunkenness.

Eye problems, such as those affecting how your eyes move, can cause misleading results in eye tests.

People should tell officers about any health problems right away and have their medical records ready. These records can help prove that the test results might not be accurate when in court.

Improper Instructions or Administration

Police officers in Colorado have to follow strict rules when giving field sobriety tests. If they don’t follow these rules, the test results might not be allowed in court. Mistakes made during these tests can help challenge DUI charges.

Not showing how to do the tests before asking someone to do them
Messing up the timing or counting in the One Leg Stand or Walk and Turn tests
Doing tests on bumpy ground or in bad lighting
Ignoring things like weather, noise from cars, or bright lights

These mistakes can be used to argue against DUI charges because the right way to do tests is needed to prove someone was driving under the influence.

Officer Bias and Subjective Interpretation

In Colorado DUI cases, field sobriety tests can be affected by officer bias and how they see things. Officers might look for signs of being drunk because they already think the person is guilty, instead of being fair and objective.

The tests involve deciding what actions like “swaying” or “using arms for balance” mean. Different officers might see these actions differently, so results can vary.

Things like the lighting, weather, or road can also change how an officer views someone’s performance on the test.

An officer’s personal history, the quality of their training, and their views on different groups of people can change how they judge the test. These personal views can make field sobriety test results less reliable as evidence in court for DUI cases.

Do You Have to Take a Field Sobriety Test in Colorado?

In Colorado, if you say “no” to field sobriety tests, you won’t face as many legal issues as if you refuse a breath or blood test.

Police can still arrest you if they think you’re driving drunk, even without the test results. Refusing the test might be talked about in court, but your driver’s license won’t be taken away, and you won’t get in trouble just for saying “no” to these tests.

Consequences of Refusing FSTs

In Colorado, drivers can say no to field sobriety tests (FSTs) without getting criminal charges or losing their driver’s license.

But there are still things to think about if you refuse the tests.

The court might think you didn’t take the test because you knew you’d fail. They could say this shows you knew you were guilty.
Police can still arrest you if they see other signs that you might be drunk, like if you’re driving all over the road, talking funny, or if your car smells like alcohol.
Saying no to the tests can be used against you in court, making it easier for the other side to prove their case.
Judges and juries might think badly of you for not taking the tests, even though it’s your right to refuse.

While you can refuse the tests, it’s important to know what might happen if you do.

How to Challenge Field Sobriety Test Evidence in Court

Challenging field sobriety test evidence in Colorado requires strategy, legal knowledge, and attention to detail. Skilled DUI defense lawyers use three main approaches: cross-examining police officers, presenting expert testimony, and exposing flaws in test administration. These methods can raise serious doubt about whether the results are trustworthy and whether the arrest was lawful.

Cross-Examining Police Officers

An experienced DUI lawyer knows that police testimony is rarely perfect. Through cross-examination, attorneys can expose weaknesses in the officer’s observations, training, and procedures. Key questions often focus on:

Environmental conditions like poor lighting, uneven pavement, or bad weather could have affected performance.
Officer qualifications, including training certifications and experience administering sobriety tests.
Instructions given, whether the officer followed NHTSA’s standardized procedures or deviated from the rules.
Personal factors, such as health conditions, fatigue, or injuries, may explain poor performance unrelated to alcohol.

By highlighting these issues, a skilled lawyer can cast doubt on the reliability of the officer’s conclusions.

Using Expert Testimony

Expert witnesses can play a critical role in challenging DUI evidence. Medical professionals, forensic scientists, or former law enforcement officers can explain how external factors may have influenced test results. For example:

Medical or neurological conditions that affect balance, coordination, or eye movement.
Age, weight, or physical limitations that make standardized tests unfair.
Environmental distractions that reduce accuracy.
Scientific critiques of the reliability and validity of field sobriety testing.

Expert testimony adds credibility to the defense and helps juries understand why test results may not prove impairment beyond a reasonable doubt.

Highlighting Flaws in Test Administration

Field sobriety tests are only reliable if officers follow strict procedures. When they don’t, the evidence can be challenged or even excluded. Common errors include:

Giving incorrect or confusing instructions that set drivers up to fail.
Conducting tests on unsafe surfaces or in poor weather conditions.
Ignoring medical conditions or physical limitations that affect performance.
Improper scoring or incomplete documentation, which weakens the evidence in court.

Identifying these flaws can significantly weaken the prosecution’s case and improve your chances of a favorable outcome.

Why Trust DUI Law Firm Denver for Field Sobriety Test Defense?

At DUI Law Firm Denver, we know how unreliable field sobriety tests can be—and we know how to challenge them in court. Our attorneys are trained in the same procedures police officers use, giving us the insight to spot errors, question flawed results, and build powerful defenses. With a proven history of dismissals and charge reductions, we fight to protect your future when a failed test puts it at risk.

Skilled Denver DUI Attorney with Proven Results

The attorney you choose can make or break your DUI case. At DUI Law Firm Denver, our lawyers have deep experience challenging the Horizontal Gaze Nystagmus (HGN), Walk-and-Turn, and One-Leg Stand tests. We know how to question police testimony, highlight medical or physical conditions that skew results, and dismantle unreliable evidence before prosecutors, judges, and juries. With our expertise, you stand a far better chance of securing reduced charges or even a full dismissal.

Deep Knowledge of SFST Training and Police Protocols

Our attorneys are trained in Standardized Field Sobriety Tests (SFSTs), just like Colorado police officers. That means we know the precise steps officers must follow, the conditions required for accuracy, and how mistakes in scoring or instruction can undermine the case against you. We also stay current with NHTSA standards and Colorado DUI laws, giving us the knowledge to expose errors, improper procedures, and unfair testing conditions, turning weaknesses in the state’s case into strengths for your defense.

History of Case Dismissals and Charge Reductions

DUI Law Firm Denver has a track record of turning questionable field sobriety test evidence into dismissed cases and reduced charges. We’ve shown courts how medical conditions, weather, uneven roads, or officer mistakes can make these tests unreliable. By identifying errors and challenging the state’s evidence at every step, we’ve helped countless clients avoid harsh DUI penalties, and we’re ready to do the same for you.

Steps to Take After a Field Sobriety Test Arrest

If you’re arrested after a field sobriety test in Colorado, the steps you take next can make or break your case. Protect yourself by acting quickly and strategically.

Document Everything Immediately

Write down every detail while it’s fresh: weather, road conditions, lighting, what the officer said, and how the test was performed. Include any health issues, fatigue, or injuries that may have affected your performance, and note the names of any witnesses. These details can expose errors or inconsistencies in police reports and strengthen your defense.

Do Not Discuss the Case Without a Lawyer

Stay silent. Anything you say to law enforcement officers, friends, family, or online can be used against you. The only person you should speak with is your lawyer, where conversations are confidential and legally protected.

Contact DUI Law Firm Denver Right Away

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Time is critical. Our attorneys can immediately request a DMV hearing within 7 days to fight for your license, preserve dashcam or bodycam video, interview witnesses while their memory is fresh, and challenge the legality of the stop or testing. The sooner you call, the stronger your defense.

You need the best DUI Attorney you can find!

Contact DUI Law Firm Denver today!

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Protect Your Rights with DUI Law Firm Denver

A DUI arrest doesn’t have to define your future. At DUI Law Firm Denver, we combine deep knowledge of Colorado DUI laws with a scientific understanding of field sobriety tests to expose errors and fight unfair charges. Our team takes a personal, aggressive approach, building a defense tailored to your case and pushing back against weak evidence. Don’t wait while the prosecution builds its case against you.

Call DUI Law Firm Denver today for a confidential consultation and take the first step toward protecting your freedom, your license, and your future.