Field Sobriety Test Errors: Deviations from NHTSA Standards

Field sobriety tests are not infallible, and their validity relies on strict adherence to NHTSA protocols, which are designed to ensure reliability and fairness. In Allsop's case, the airport police officer administered three standard tests: Horizontal Gaze Nystagmus (HGN), Walk-and-Turn (WAT), and One-Leg Stand (OLS). However, the transcript reveals multiple deviations that could undermine the results in court. These tests are only about 68-88% accurate when done correctly, and errors like these often lead to suppressed evidence or dismissed charges.

• Horizontal Gaze Nystagmus (HGN): This test checks for involuntary jerking of the eyes as they follow a stimulus (e.g., a pen), which can indicate impairment. NHTSA requires officers to first screen for medical issues (e.g., head injuries), check for equal pupil size and tracking, and then test for lack of smooth pursuit, distinct nystagmus at maximum deviation, and onset before 45 degrees—repeating each pass twice per eye. In the transcript, the officer simply instructed Allsop to "follow the tip of my pen with your eyes only." During the Lack of Smooth Pursuit (LSP), the Officer only performed one pass for each eye, NHTSA guidelines require 2 passes for each eye on LSP. On distinct and sustained nystagmus at maximum deviation, 2 passes were performed on the left eye and three passes on the right eye. On nystagmus prior to onset of 45 degrees, these passes were skipped entirely. No details on pupil checks or equal tracking are noted, but the administration appears rushed and was incomplete. The officer later mentioned seeing "nystagmus", but without proper protocol, this clue is unreliable. The minimum number of clues for nystagmus to indicate a correct arrest decision is 4/6 clues. This test was incomplete and should be excluded. At best, this evaluation can only demonstrate the presence of alcohol or one of the other 43 known conditions and compounds that can cause horizontal gaze nystagmus. 
• Walk-and-Turn (WAT): NHTSA standards mandate a straight line (real or imagined), hands at sides, 9 heel-to-toe steps forward (touching heel to toe within 1/2 inch), a specific pivot turn (keeping front foot planted and taking small steps with the back foot), and 9 steps back—while counting out loud and not stopping. Clues include balance loss during instructions, wrong step count, raising arms over 6 inches, or improper turn. Here, the officer completely skipped the instruction phase of the walk and turn as the pilot was not placed in the NHTSA specific starting position before the instructions began. Second, the officer instructed Allsop to take 10 steps (not 9), allowed "arms out for balance" (contrary to hands at sides), and gave vague turn directions ("turn around and go the other way") without specifying the pivot. Allsop took 9 steps forward and 10 back, which mismatches the standard. The test was on an "incline" surface, potentially invalidating results, and the officer noted no clear clues in WAT but proceeded anyway.
• One-Leg Stand (OLS): The subject must raise one foot 6 inches off the ground, parallel to the floor, hands at sides, look at the toe, and count "one thousand one, one thousand two" until told to stop (typically 30 seconds). Clues: swaying, using arms, hopping, or putting foot down. In the transcript, instructions were "put your foot out in front of you like this" and "count out loud 1,00 2 1 3 100 to stop"—missing details on height, parallel position, or looking at the toe. Allsop was stopped after about 16 seconds (at "1600"), short of the full 30, and his counting skipped numbers (e.g., no "4" or "10"). The officer claimed on video no clues on the walk and turn and one leg stand only notating nystagmus. 

These errors aren't minor—they violate NHTSA's emphasis on standardization to avoid false positives. In Georgia courts, we've used similar flaws to argue that FST results are inadmissible, often leading to reduced charges or acquittals.

Misreading Georgia's Implied Consent Law: 0.08 vs. 0.04 for Aircraft

Georgia's implied consent law requires drivers to submit to chemical testing if arrested for DUI, with refusal leading to license suspension. The officer read the standard vehicle version from O.C.G.A. § 40-5-67.1(b)(2) for those over 21, warning of suspension if results show "0.08 grams or more" alcohol concentration. But Allsop wasn't driving a car—he was preparing to pilot an aircraft, governed by O.C.G.A. § 6-2-5.1, which sets a stricter limit: no operation or physical control if there's "0.04 percent or more by weight of alcohol in his blood," or within 8 hours after consuming alcohol.

This misreading is critical. While aircraft DUI testing follows procedures in § 40-6-392(a) (e.g., blood/breath tests) for automobile drivers, the per se limit is 0.04—not 0.08. Allsop admitted to drinking "a few beers" about 10 hours prior, which might clear the 8-hour rule, but the officer's incorrect advisement could invalidate the refusal's consequences. Refusals are powerful evidence for prosecutors, but if the warning is flawed, it may not hold up. We've challenged similar errors to suppress refusal evidence, turning cases in our clients' favor.

Was the Investigative Detention Legal? Odor Alone, Parked Plane, and "Actual Physical Control"

The arrest stemmed from a TSA report of an alcohol odor on Allsop's breath at a Known Crewmember (KCM) checkpoint. Officers then detained him for investigation. For a Terry stop (investigative detention), police need reasonable articulable suspicion of criminal activity—not probable cause. Here, the odor (confirmed by the officer) and admission to prior drinking provided suspicion, but was it enough for an aircraft DUI?

Key issue: The plane was parked at the gate, engines off, boarding not started—operation hadn't begun. Georgia law prohibits "operate or be in actual physical control" of an aircraft while impaired. "Actual physical control" means movement. Allsop was in the cockpit area, scheduled to fly, but the aircraft had not moved. However, if no intent to operate was proven (e.g., plane not moving, no pre-flight actions), detention might be premature. TSA agents aren't trained in DUI detection, and odor alone doesn't always justify extended detention without other signs like slurred speech, glassy eyes or unsteady gait (none noted initially).

In vehicle DUIs, we've won motions to suppress when detention relies solely on odor without evidence of driving or control. For pilots, FAA rules add layers (e.g., no alcohol within 8 hours), but state law governs the charge. This case highlights how aviation DUIs blend state and federal standards—errors here could lead to dismissal.

What This Means for You: Protect Your Rights in DUI Cases

David Allsop's arrest underscores how even professionals can face flawed investigations. If charged with DUI—on the road, water, or in the air—don't assume the evidence is ironclad. Procedural errors like these are common, and an experienced attorney can exploit them to your advantage.

At George C. Creal, Jr., P.C., we specialize in Georgia DUI defense, including aviation and commercial cases. We've handled thousands of arrests, often getting charges reduced or dismissed by challenging FSTs, implied consent readings, and detentions. If you're facing a DUI, contact us today for a free consultation. Remember, time is critical—call (404) 333-0706 or visit georgecreal.com. Your career and freedom may depend on it.

Disclaimer: This post is for informational purposes only and not legal advice. Case outcomes vary.

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