Cross-Examination on Horizontal Gaze Nystagmus in a Drunk Driving Case

Attorney - Well, we don't know, do we? Because you did not check. What was the amplitude of nystagmus at the maximum lateral deviation?
Officer - The what?

Attorney - The degree of eye jerking at the furthest movement of the eye, Sergeant.
Officer - Maximum deviation, yes, there was distinctive jerking at the maximum deviation.

Attorney - But what was the amplitude?
Officer - I didn't really notice.

Attorney - Did you consider "smooth pursuit" as a factor in the nystagmus test?
Officer - I did.

Attorney - And did you consider this an accurate indication of intoxication?
Officer - I did.

Attorney - As accurate as onset?
Officer - Yes.

Attorney - You place a lot of weight on it?
Officer - I suppose so, yes.

Attorney - Then, again, you disagree with NHTSA? (Reading) "Smooth pursuit eye movement... is the least reliable of the three signs."
Officer - My understanding was that all three were equally reliable.

Attorney - Sergeant, what was my client's score on your nystagmus test?
Officer - Score?

Attorney - Yes, what was his total score on the test?
Officer - There's no score, counselor. You either pass or fail. He failed.

Attorney - (Feigning surprise) Then your test is entirely subjective?
Officer - It is based upon my observations.

Attorney - YOU decide whether he passed or failed?
Officer - Of course.

Attorney - Why do you choose not to use an impartial, objective scoring system?
Officer - You can't score a nystagmus test, counselor. Either the jerking indicates intoxication or it doesn't.

Attorney - Are you aware that NHTSA recommends an objective scoring system?
Officer - I am not.

(Attorney has the officer review the report.)

Attorney - Have you now reviewed NHTSA's scoring sheet?
Officer - I have.

Attorney - Apparently, using the objective system, four of six possible points indicates failure, right?
Officer - Apparently.

Attorney - Do you still think it's not possible to use an objective method for deciding whether a person passes or fails the test?
Officer - I suppose it's possible, but it's not how we were trained.

Attorney - Sergeant, you've read the NHTSA law enforcement booklet, Guide for Detecting Drunk Drivers at Night?
Officer - I think that was in the stuff you mailed me.

Attorney - Isn't it true that NHTSA studies indicate that even if nystagmus is administered exactly as recommended, the test has only a 77 per cent reliability factor?
Officer - That's what it says.

Attorney - So, even if the test is done as recommended, you will be right only three out of four times?
Officer - Apparently.

Attorney - Even if you gave the test as recommended, one-fourth of those who "fail" will be... innocent?
Officer - Apparently.

Attorney - And you admit that you did not give the test as recommended?
Officer - I gave it the way I was taught.

Horizontal Gaze Nystagmus
Excellent article summarizing facts/issues on the "HGN" field sobriety test ("follow the pen with your eyes"), from the University of Missouri Law School.

The Science and the Law
A resource guide for judges, prosecutors and law enforcement that deals with Horizontal Gaze Nystagmus.

DUI Arrest FAQs
The 20 questions most frequently asked by those arrested for DUI, from a California lawyer.

California DUI: A Drunk Driving Law Guide is intended to counter the political pressures of extremist groups seeking the passage of unfair laws, the erosion of constitutional rights and the eventual return of prohibition. The National Motorists Association sets forth its positions on controversial drunk driving issues, such as unconstitutional roadblocks, overemphasis on breath alcohol tests, unfair criminal penalties and the imposition of "automatic" license suspensions. See also "Responsibility in DUI Laws, Inc.", an organization dedicated to reforming harsh and misdirected DUI laws.

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