logo for print

How the art of conversational interrogation will improve your DWI investigations

Most real-life police interviews contain many undesirable practices – here’s how to improve them


Policing has evolved immensely since Sgt. Joe Friday went around in his white shirt, narrow tie, gray suit and fedora hat investigating crimes with his iconic, “Just the facts, ma’am.” But to look at DWI investigations, you wouldn’t know it.

Understanding the why of DWI investigations

What’s the purpose of stopping someone suspected of DWI?

You can have all the evidence in the world, but if jurors don’t find the investigating officer credible, they will doubt the credibility of the evidence the police officer gathered. (Photo/Pixabay)
You can have all the evidence in the world, but if jurors don’t find the investigating officer credible, they will doubt the credibility of the evidence the police officer gathered. (Photo/Pixabay)

1. To determine if they are, in fact, driving impaired.

And, if they are…

2. To gather as much legally admissible evidence of that as possible.

Accomplish this, and often the case won’t go to trial. If it does go to trial, there’s a third element of an unbeatable DWI investigation.

3.  A testifying officer the jurors trust and believe.

You can have all the evidence in the world, but if jurors don’t find the investigating officer credible, they will doubt the credibility of the evidence the police officer gathered.      

Understanding the how of DWI investigations

How can you best accomplish the three steps above? Conversational interrogation. That may sound like an oxymoron – but it needn’t be.

Yes, your questioning of a DWI suspect is, in the legal sense, an interrogation – a series of questions reasonably calculated to produce an incriminating response. But there’s no requirement that it not be conversational. Moreover, conversational interrogation is much more likely to produce an iron-clad DWI case.

In Let ’Em Talk! A Field Study of Police Questioning Practices of Suspects and Accused Persons, the authors summarize some core components that are fundamental to thorough and professional information-gathering interviews:

  • Ask as many open-ended questions as possible.
    Such questions can’t be answered with “yes” or “no.” Open-ended questions encourage free recall and allow for a wide range of responses. They typically start with “tell,” “explain,” or “describe.” For example, “Tell me what you’ve been doing today?” or “Other than being stopped by me, how’s your day been going?” Open questions get people to expand on information and can get a reserved person talking.  
  • Listen actively and don’t interrupt.
    A rule that encourages active listening is the 80-20 talking rule where the interviewer talks 20% of the interview time and listens 80%. When you’re talking, the DWI suspect isn’t providing information. Field studies show this rule is pervasively broken, with interviewers typically consuming most of the interview time.
  • Avoid closed yes–no questions.
    Questions like, “Do you know why I stopped you?” or “Have you been drinking?” have the potential to extract incomplete or inaccurate answers, or intimidate the interviewee. In social settings and investigations, closed questions can kill a conversation. 

Despite experts agreeing on what constitutes best practices, field studies of police interviews – especially where officers have not been appropriately trained – show that most real-life police interviews contain many undesirable practices such as asking many more closed than open-ended questions.

In one of the first field studies exploring witness interviewing practices, researchers analyzed 11 video-recorded witness interviews and found that questions consisted mostly of closed yes-no questions – described as being delivered in a staccato style – and only three open-ended questions were asked per interview. On average, only 10% of questions composing an interview consisted of open-ended questions.

Similarly, later research found that 73% of the questions asked by untrained investigators were closed yes-no questions, and only 2% were open-ended. This inappropriate style of questioning has been documented routinely since.

The advantages of conversational interrogation

Clay Abbott, a nationally recognized expert and DWI Resource Prosecutor for the Texas District and County Attorneys Association (TDCAA), contends that conversational interrogation produces:

  • More cooperative suspects who will give you more information freely. The more people talk, the more they like you. The more they like you, the more they’ll talk.
  • More credibility for the police officer in court. An officer who is friendly and conversational in tone will be seen as open-minded, fair and without an agenda. Jurors will trust such an officer.

Abbott also acknowledges that officers universally perform this aspect of a DUI investigation poorly. That’s why, in conjunction with the TDCAA, he helped produced a 20-minute training video titled Effective Roadside Investigation Through Conversation that includes examples of non-conversational and conversational interrogations.

Tips for a DWI roadside conversation

Rather than ask the suspect, “Do you know why I stopped you?” (close-ended), Abbott recommends – after you politely introduce yourself – to tell the person why you stopped them. This gets your probable cause on video and, by explaining your actions, you appear respectful and fair.

During a conversational roadside investigation, police officers should consider doing the following:

  • While the driver is producing registration and proof of insurance, the officer asks, “Where are you coming from?” (open-ended). This divides the suspect’s attention, which may well reveal impairment.
  • The officer tells the suspect he smells alcohol (thereby putting it on video and getting the jury to smell it) and then asks, “What have you had to drink?” (open-ended). When the suspect says, “Two margaritas?” the officer asks, “What size?” (open-ended). When the suspect replies, “Normal size,” the officer follows-up with, “Anything else?”
  • Additional questions relevant to a DWI conversation might include:
    • Where are you headed?
    • How long have you been driving?
    • How familiar are you with this vehicle?
    • Does the vehicle have any problems?
    • Tell me about any medical or other conditions that could affect your driving?  
    • Could you please step out of the car? I just need to have you perform some tests so I can make sure you’re safe to drive.

As important to whether the questioning is mostly open or closed-ended, is the officer’s tone. It should be conversational, interested, non-judgmental and concerned.

Remember the purpose of a DWI investigation. Conversational interrogation is the best way to accomplish it – roadside and in the courtroom.

Author's Note: Thanks to Corporal Joe Miller, of the Alaska State Troopers, for bringing this topic to my attention.

Request product info from top Traffic Enforcement companies

Thank You!

Thank You!

By submitting your information, you agree to be contacted by the selected vendor(s).

Join the discussion

Brand focus

Sponsored content
4 ways license plate readers can boost your agency's effectiveness

4 ways license plate readers can boost your agency's effectiveness

Increase patrol officers’ productivity and enhance your agency’s investigative reach using LPR cameras and hot list data

Copyright © 2018 PoliceOne.com. All rights reserved.