Exposing NHTSA Phase One Bias: A Powerful Cross-Examination Tool in Ohio OVI Cases

When someone is charged with an OVI in Ohio, it often feels as though the entire system is stacked against them. Officers talk about standardized training, scientific procedures, and field sobriety protocols as if they are objective and neutral. But beneath the surface of the National Highway Traffic Safety Administration (“NHTSA”) Standardized Field Sobriety Testing system lies a flaw that experienced defense attorneys can use to shift how juries see the case. That flaw appears before an officer ever speaks to a driver. It is called Phase One bias, and when exposed through cross-examination, it can dramatically change the credibility of the officer’s testimony.

Phase One bias is not something that shows up halfway through the investigation. It is embedded in the officer’s training from the very beginning. Once jurors understand how this bias works, they begin to question whether the officer’s observations were neutral or shaped by a mindset trained to look for impairment before any real evidence existed.

Understanding the NHTSA SFST System

NHTSA divides OVI investigations into three phases. Phase One: “Vehicle in Motion” is the officer’s initial observation of the vehicle. Phase Two involves face-to-face interaction with the driver. Phase Three consists of the standardized field sobriety tests.

Ohio courts accept these phases as the backbone of roadside investigations. Officers can testify about field sobriety tests as long as they substantially comply with NHTSA standards. While this framework often appears to favor the prosecution, it also exposes a critical weakness: the system quietly primes officers to search for impairment from the moment they see a vehicle.

The Hidden Bias in Phase One Training

During Phase One, officers observe a moving vehicle before any contact with the driver. At this point, they cannot smell alcohol, hear slurred speech, or observe coordination issues. They have no direct evidence of impairment.

Yet the NHTSA manual instructs officers to “concentrate on specific evidence that may suggest the driver is under the influence.” Not neutral evidence. Not evidence that rules out impairment. But specifically evidence that suggests impairment.

This creates a confirmation-focused mindset long before an officer has any factual basis to believe the driver is impaired. The manual claims officers are “not committed to arrest” during Phase One, but the instruction to search for signs of impairment pushes them toward a conclusion they have not yet earned. That contradiction is a powerful point to expose at trial.

Strategic Cross-Examination: Showing the Bias

A powerful cross-examination does more than ask questions. It walks jurors step by step through the officer’s own training until they see the flaw in the system for themselves.

It starts with the basics. The officer confirms they were trained using the NHTSA Standardized Field Sobriety Testing course. They agree the manual is the backbone of how they conduct OVI investigations. Once that foundation is in place, the cross shifts to Phase One — the moment before any contact with the driver. The officer must acknowledge, one controlled question at a time, that in Phase One they have not yet smelled the driver’s breath, heard their speech, or observed their coordination. They are operating without a single confirmed sign of impairment.

Then the cross gives jurors the key that unlocks everything. The attorney directs the officer to NHTSA’s own language: during Phase One, officers are told to “concentrate on specific evidence that may suggest impairment.” When the officer admits that this instruction appears exactly in the manual, the point lands. The officer did not begin this encounter neutrally. Their training told them to start the stop already looking for signs of impairment.

From there, the logic becomes unavoidable. If an officer is trained to search for impairment before speaking to the driver, every later observation is filtered through that lens. Ambiguous behavior becomes suspicious. Normal driving becomes “possible impairment.” What should be a neutral investigation becomes one shaped by expectation. And jurors begin to see that the bias doesn’t just affect Phase One — it colors the entire investigation from start to finish.

Why Juries Find This Persuasive

This strategy connects with jurors because it feels true to real life. Everyone knows that when you expect to see something, you are more likely to “find” it, even when the facts do not truly support it.

Jurors also appreciate that this argument does not accuse the officer of lying. Instead, it shows how the training itself nudges officers toward a conclusion before the evidence is fully developed. Once jurors see how early the bias enters the process, they begin to question the reliability of every subsequent observation, from the initial stop to the field tests.

A Real-World Example

Imagine an officer driving behind a vehicle traveling slightly under the speed limit late at night. Under Phase One training, that cautious driving becomes a “possible clue” of impairment. The officer initiates a stop.

During Phase Two, the officer claims to detect a faint odor of alcohol or notes the driver appears “nervous.” During Phase Three, the driver struggles with balance on uneven pavement or in cold weather. Each observation builds on the last, reinforcing the officer’s belief that impairment is present.

But when this sequence is examined under cross-examination, the bias becomes clear. The slow driving might simply reflect caution. The odor could come from a passenger. Nervousness is completely normal during a police encounter. And field sobriety tests are notoriously difficult, even for sober individuals.

Once jurors see how Phase One bias shaped everything that followed, the prosecution’s narrative begins to lose strength.

Protecting Your Rights Against Biased Investigations

Exposing NHTSA Phase One bias is only one part of building a strong OVI defense. The system appears scientific, but it contains structural weaknesses that trained attorneys can use to challenge the State’s case.

At Harmony Law, we understand how confirmation bias influences roadside investigations. We study NHTSA protocols closely and use strategic cross-examination to reveal flaws that many people never notice. When facing an OVI charge, you deserve a defense that understands both the science and the subtle biases that drive these investigations.

If you are facing OVI allegations in Ohio, do not assume the officer’s observations tell the full story. Contact Harmony Law today to discuss how we can challenge the State’s evidence and protect your rights.