Circumstantial Evidence in DUI Cases

In criminal matters, prosecutors may use either direct or circumstantial evidence to establish guilt. For example, if the police find a gun belonging to the defendant at a murder scene, that is circumstantial evidence of guilt; if the defendant admits to killing the victim during interrogation, that is direct evidence of guilt. Both types of evidence may or may not be admissible, but that is the subject of another blog.

Operating a Motor Vehicle

There are basically three elements in a DUI: driving a motor vehicle while under the influence of alcohol, drugs, or a combination of these substances. Almost anything that rolls or floats is a motor vehicle, even if it does not have an independent means of propulsion, so this element is fairly easy to establish. But what about the other two?

The defendant does not have to be “driving” the vehicle in the ordinary sense of the word to be convicted of DUI: the statute is clear that “actual physical control of any vehicle within this State” is sufficient. So, a person can be parked at a corner or idling outside a house and be charged with DUI.

Typically, there is direct evidence on this point because the arresting officer saw the defendant driving or operating the vehicle. DUI crash cases, the arresting officer did not see the defendant drive or operate the vehicle. If there was more than one occupant in the car, or there are other unusual circumstances, it may be difficult for the prosecutor to establish that the defendant was driving or operating the vehicle, based solely on circumstantial evidence.

Under the Influence

In about 80% of cases, there is direct evidence of intoxication because the driver agreed to take a breath or blood BAC test. In the other 20%, the prosecutor must rely on circumstantial evidence. This evidence nearly always comes from Field Sobriety Tests. Field Sobriety Tests are optional. Unless ordered to do so, the defendant has a right to walk away or refuse testing.

In many jurisdictions, officers force suspects to perform a number of unapproved FSTs, like reciting part of the ABCs or touching their fingertips to their noses. Although these tests may not be admissible as circumstantial evidence of intoxication, they fatigue the suspects both mentally and physically so they may not perform as well on the tests that count. That is why officers typically administer the unapproved FSTs before the approved ones, which are:

  • Walk And Turn (walking a straight line),
  • One Leg Stand, and
  • Horizontal Gaze Nystagmus.

The WAT and OLS have both mental and physical components because they measure both the suspect’s ability to follow directions and degree of coordination. Testifying officers always maintain that the suspects “failed” the tests even if they performed fairly well, and so the jury decides whether or not the suspects “passed” the tests or not. The HGB is about 85% accurate if administered under ideal conditions, and so once again, it is up to the jury to assign a weight to this test.

Partner with Experienced Attorneys

For an effective defense in cases that involve circumstantial evidence, reach out to an experienced criminal defense attorney in Schaumburg from Glasgow & Olsson. We routinely handle matters in Cook County and nearby jurisdictions.

(photo courtesy of Matt Rostle)

This entry was posted in: 

And tagged: