U.S. Supreme Court Considerers DUI Evidence and Search Warrants

During recent oral arguments, the US Supreme Court Justices were skeptical of laws in nearby Minnesota, and twelve other states, which make it a crime for drivers to refuse intoxication tests.

Several Justices appeared to seek a middle ground, since the Court currently has only eight members. Justice Stephen Breyer spoke for several of his colleagues when he said that states could render the matter moot by simply obtaining warrants prior to these tests. He stated that it takes only five minutes to get a warrant in Wyoming and fifteen minutes in Montana. Justice Elena Kagan suggested that the states could declare a Breathalyzer test to be a warrantless search incident to an arrest because such a procedure is “about as uninvasive as a search can possibly be.”

A decision in the case is expected by June.

Chemical Evidence

In Illinois, a BAC of .08 or above is only a presumption of intoxication, even though some jurors mistakenly believe, and some prosecutors strongly imply, that a .08 is conclusive proof of the matter. Like all machines, Breathalyzers are not perfect. In fact, they suffer from a number of flaws, including:

  • Mouth Alcohol: Illinois requires officers to observe suspects for fifteen minutes prior to a breath test because any burping or belching forces alcohol molecules into the mouth and skews the test. The waiting period is often an issue when multiple officers are at the arrest scene.
  • Acetone: Diabetes, smoking, and grain consumption all produce greatly elevated acetone levels, and this substance registers as alcohol in chemical tests.
  • Absorptive Phase: If the subject just drank recently, alcohol is still in the blood and the BAC will be artificially high.
  • Temperature: Breathalyzers are very sensitive devices, and most of them do not self-calibrate to account for heat or cold.

Many times, an attorney can partner with an engineering or medical student to provide compelling expert testimony at little cost.

Non-Chemical Evidence

About one in five drivers refuse consent to provide a chemical sample, meaning that the officers must either obtain a warrant or rely on circumstantial evidence; the vast majority of DUI refusals involve the latter.

The National Highway Transportation Safety Administration has approved three field tests for use in DUI prosecutions. They are:

  • Walk and Turn,
  • One-Legged Stand, and
  • Horizontal Gaze Nystagmus.

The first two tests measure cognitive ability (did the suspect follow directions) and physical dexterity (balancing on one leg or walking a straight line). Many drivers have limited English proficiency or are too nervous to listen to directions, so the cognitive measurement may be misleading. It further stands to reason that suspects who are too nervous to listen to directions may also have difficulty controlling their muscles.

While the HGN test (follow a light or fingertip with your eyes without moving your head) is over 80% effective in predicting intoxication when the test is conducted under controlled conditions, a roadside test can hardly be considered a controlled environment.

Reach Out to Aggressive Attorneys

Given the inherent flaws in DUI evidence, it is difficult for prosecutors to prove guilt beyond a reasonable doubt. For a confidential consultation in this area, contact an experienced Schaumburg criminal defense attorney from Glasgow & Olsson. Convenient payment plans are available.

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