The eyes have it

At the side of the road, law enforcement routinely makes DUI arrests based upon results of a Horizontal Gaze Nystagmus (HGN) test. The underlying premise of the test is: you drink enough alcohol, and then you eyes will show HGN.

Alcohol, however, is not the sole cause of HGN. In State v. Horn, the court recognized the following causes or possible causes of HGN:

  • problems with the inner ear labyrinth;
  • irrigating the ears with warm or cold water;
  • influenza; streptococcus infection;
  • vertigo;
  • measles;
  • syphilis;
  • arteriosclerosis;
  • Korchaff's syndrome;
  • brain hemorrhage;
  • epilepsy;
  • hypertension;
  • motion sickness;
  • sunstroke;
  • eye strain;
  • eye muscle fatigue;
  • glaucoma;
  • changes in atmospheric pressure;
  • consumption of excessive amounts of caffeine;
  • excessive exposure to nicotine; aspirin;
  • circadian rhythms;
  • acute head trauma;
  • chronic head trauma;
  • some prescription drugs; tranquilizers,
  • pain medication,
  • anti-convulsant medicine;
  • barbiturates;
  • disorders of the vestibular apparatus and brain stem;
  • cerebellum dysfunction;
  • heredity;
  • diet;
  • toxins;
  • exposure to solvents;
  • extreme chilling;
  • eye muscle imbalance;
  • lesions;
  • continuous movement of the visual field past the eyes; and
  • antihistamine use.

 

Read the "Warning Label" of your blood test

When should you trust a blood test result that claims to measures an alcohol concentration?  Start by reading the test's "Warning Label."  Here is an explanation on my legalcoffee blog.

Blood Testing Is About More Than A Machine

In DUI cases, an accurate blood test result requires more than just the blood tester to be working properly. A reliable test results requires more than than what the machine (the blood tester) provides.  As shown below, see the machine is just a fraction of the process need to obtain an accurate and reliable result.

Usually the government only puts safeguard in place to prevent machine errors.  Consequently the majority of the blood testing process will go unchecked and subject to human error.       

 

Wonder Bread Does it Again!

It turns out my previous post showing Wonder Bread causing a false blood alcohol concentration reading was not an isolated incident.  The same forensic toxicologist and drug recognition expert did another Wonder Bread experiment.  Here it is:

 

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