OWI INVESTIGATION REVIEW

Understanding where an impaired-driving investigation can go wrong.

THE THREE PHASES OF AN OWI INVESTIGATION

An OWI investigation develops in stages. What an officer observes during each stage determines whether the investigation should continue to the next. I review these cases in the same order the officer experienced them: the driving behavior, the initial contact with the driver, the roadside investigation, SFSTs, the legal basis for requesting a PBT, and ultimately the decision to arrest.

1. VEHICLE IN MOTION

The first thing I look at is why the vehicle was stopped and what the officer actually observed before making contact with the driver. I routinely saw weaving or a tire touching the rumble strips described as a “deviation from designated lane,” even though the facts did not necessarily establish the traffic violation being claimed. I also saw stops based on things like supposedly dim registration lamps or other equipment violations where the officer’s description did not always match what the video showed or what the law actually required.

The reason for the stop and the driving behavior matter. I compare what the officer wrote in the report with the squad video and the actual traffic violation being alleged. A report describing “poor driving” or a “lane deviation” does not tell me much by itself. I want to see exactly what the vehicle did and whether the officer accurately described it.

2. PERSONAL CONTACT

Once the officer gets to the window, I look at what physical signs of impairment were actually present before the officer began asking about alcohol or drugs. In my experience, when there were few obvious signs, officers often relied heavily on getting an admission. Questions about drinking, marijuana, prescription medication, or other drug use could be repeated several times, often with some version of “this is your opportunity to be honest.”

Once an admission was made, the direction of the investigation often changed. The driver would be asked to perform SFSTs, and observations made afterward could be interpreted through the assumption that the driver was impaired. An admission to drinking, using a drug, or taking prescription medication is important information, but it is not the same thing as evidence that the person was impaired at the time they were driving.

I also look closely at observations such as pupil size and reaction to light. I have seen officers document constricted pupils without being able to explain which drug categories are associated with constriction, or incorrectly associate constricted pupils with methamphetamine even though CNS stimulants are generally associated with dilation. I have also seen officers document a “slow reaction to light” without being able to explain what that term actually means.

3. PRE-ARREST SCREENING

This is where my experience as an SFST instructor and Field Training Officer becomes especially useful. I routinely saw officers struggle with the basic administration and interpretation of SFSTs. Instructions were incomplete, questions were not clearly answered, medical issues were not properly ruled out, and officers sometimes relied more on “how I’ve always done it” than what they were actually trained to do.

With HGN, I look at the entire administration, not just the number of clues the officer reports. Officers may fail to properly check for resting nystagmus, equal pupil size and equal tracking, start portions of the test with the wrong eye, improperly position the stimulus, or not maintain the proper distance from the subject’s face. I have encountered officers who could not explain these procedures when asked, or did not know they were required.

The same issues occur with Walk-and-Turn and One-Leg Stand. I have seen officers stop during their own Walk-and-Turn demonstration, walk alongside the subject during the test, fail to verify that the instructions were understood, or score movements as clues that are not identified as clues under the standardized criteria. Even simple things get missed, such as having someone remove their glasses for HGN and then never telling them to put the glasses back on before the walking and balance tests.

I am not looking for minor differences just to say an officer did something wrong. I look at whether the test was administered and interpreted properly, whether the claimed clues are actually supported by the video, and whether any mistakes matter to the conclusions the officer ultimately reached.

THE PBT AND PROBABLE CAUSE

One of the most consistent problems I saw as a Field Training Officer and police academy instructor was the routine use of a PBT regardless of whether the investigation had actually developed the legal threshold required to request one. In practice, the PBT was treated almost like another step of the SFSTs.

Wisconsin Statute § 343.303 allows an officer to request a PBT when the officer has “probable cause to believe” the person is violating or has violated Wisconsin’s OWI law. That standard is lower than the probable cause required to arrest, but the legal basis to request the PBT still has to exist before the officer knows the result.

The problem is that many questionable PBT requests never get litigated. If the driver blows .04, the officer may release the driver with a warning and the case ends. If that same driver, with the same driving behavior, the same physical observations and the same SFST performance, blows .10, the driver is likely getting arrested.

That is why I look closely at what the officer actually knew before requesting the PBT. The PBT can be considered when deciding whether to arrest. It should not be used to go back and justify the observations and conclusions that were necessary to request the PBT in the first place.

A COMMON EXAMPLE

A driver is stopped late at night after touching the fog line twice. At the window, the driver has normal speech, normal motor coordination, produces a license without difficulty, and has slightly bloodshot eyes. After repeated questioning, the driver admits to having two beers with dinner several hours earlier.

The driver is asked out of the vehicle and performs SFSTs. Assume the driving, the officer’s observations, and the driver’s SFST performance are exactly the same in both cases.

If the PBT is .04, the driver may be released with a warning and the investigation is over. If the PBT is .10, that same driver is likely arrested.

When I review a case like this, I work through it chronologically. What did the officer actually observe before the PBT? Were the SFSTs administered and interpreted correctly? Were the claimed clues actually visible on video? Most importantly, did the officer have the legal basis required by Wis. Stat. § 343.303 to request the PBT before knowing what number it would produce?

A higher PBT result can be considered in the arrest decision. It cannot go back in time and create the legal basis required to request the test.

WHY THESE DETAILS MATTER

Each phase builds upon the one before it. When observations are inaccurate, procedures are administered incorrectly, or evidence does not support what was documented, those issues can affect later decisions in the investigation, including field sobriety testing, a PBT, probable cause, and arrest.

An expert review identifies those issues and explains why they matter.