Four Pillars of a DUI Case

In any DUI case, whether a misdemeanor DUI or felony DUI, the prosecutor will always rely on four major categories of evidence to try to prove the defendant’s guilt. We consider these four areas to be like four legs of a table. If we can raise doubt, and knock out one of the legs of the table, it will be so wobbly that it will likely fall over. If we can knock out two of the legs, what started out as a table is now just a hunk of wood on the ground… it doesn’t even deserve to be called a table anymore!

These four areas are:

• Driving patterns;
• Physical signs and symptoms;
• Field Sobriety Test performance;
• Chemical test results (or the refusal to test, which will be used to try to
show “consciousness of guilt”)

The driving pattern that the defendant engaged in prior to the stop can be a very fertile area for attack. The National Highway Traffic Safety Administrative (NHTSA) has done some fairly exhaustive research into the top clues for detecting impaired drivers, and if the cause for the stop isn’t on there (such as speeding), there’s quite a bit that can be done. Other driving patterns frequently cited by officers, such as weaving, require specific elements to be satisfied, and if they aren’t, the entire case can be thrown out by way of a Motion to Suppress Evidence.

Physical signs and symptoms are frequently the easiest pillar to attack. These include things like red, watery eyes; odor of alcohol on the breath; slurred speech; or unsteady gait. Usually these items show up as a “check the box” list of symptoms on a police report template. Once it is demonstrated that an officer did an inadequate investigation to rule out common causes of these problems, or to show that they could have been easily documented by a photo or tape- recording (but the officer didn’t bother), they are easily side-stepped.

Field Sobriety Test performance can be a fantastic area for the defense. Although law enforcement officers routinely conclude that the DUI defendant “failed” the test, when we explore each of the elements of these roadside exercises, we frequently see that our clients actually do 95 out of 100 things correctly, and that the officer is simply unfairly biased and only focused on those few things that are done wrong. In our experience, any test where someone gets 95% right is an “A” and not an “F”!

Chemical test results often seem like a straightforward issue, but there are at least 50 reasons
that breath and blood testing results can be in error, and even at their best only indicate
someone’s alcohol level at the time of testing, and not the time of driving, which is the only
time that matters under California’s DUI laws.

Direct vs. Circumstantial Evidence

All of this evidence, from each of the four pillars of the case, is circumstantial evidence, because
it is evidence of one thing from which judges or jurors are being asked to draw an inference,
namely that the defendant was under the influence or that they were above the legal limit at
the time they were behind the wheel.

This can get very complex, but there is one critical thing to know about when it comes to
circumstantial evidence:

Where there are two reasonable inferences to be drawn from any item of circumstantial
evidence, one that points to guilt and the other that points to innocence, the judge or jury
must disregard the one that points to guilt, and embrace the one that points to innocence!

This rule, when used by an effective DUI defense attorney, may be the most important thing to understand in criminal law, more important than the requirement that guilt be proven beyond a reasonable doubt.