Although DUI/DWI law can vary from one state to the next, a person can still be prosecuted and convicted for DUI even though a chemical test of the person’s bodily fluids (breath, blood, or urine) is not available to the prosecutor.
There are several reasons that chemical test results may not be available to the prosecutor. Below are some of them.
Some states give a suspect the right to refuse a police officer’s request that the suspect provide a breath, blood, or urine sample (some states, however, allow law enforcement to obtain a warrant to draw blood from the suspect even though the suspect is unwilling to voluntarily provide a sample). Although some jurisdictions do allow a suspect to refuse testing, refusing law enforcement’s request to submit to a chemical test carries penalties, such as suspension of the suspect’s driver’s license.
Chemical tests results may also be unavailable because of testing equipment malfunctioning.
Another reason that test results of a suspect’s bodily fluids may not be available to the prosecutor is because the judge has ruled that the sample collected is inadmissible during trial. This scenario usually results from the suspect’s lawyer having successfully argued to the judge that law enforcement violated the suspect’s constitutional rights in obtaining a sample of the suspect’s bodily fluids. Or the defense attorney may successfully argue that the manner in which the authorities collected the sample did not comply with federal or state procedures.
When a suspect challenges a test’s admissibility, a hearing is held before trial without a jury, so the test and the results are not made known to the jury during the suspect’s trial if the judge rules that they are not admissible during trial.
When a chemical test of the suspect’s bodily fluids is not available, the prosecutor can still pursue a DUI prosecution. Referred to as “DUI less safe” by some jurisdictions, these state laws provide definitions of DUI that do not contain as an element a threshold alcohol level, above which the defendant is considered legally intoxicated. Instead, under these alternative definitions of DUI, the prosecutor has to prove only that the defendant ingested some alcohol and as a result drove less safely than the defendant would have driven without having consumed any alcohol.
In such cases, the prosecutor at trial often will introduce evidence such as the officer’s testimony and video of the defendant’s performance in field sobriety tests. Field sobriety tests are tests that the officer subjects the driver to, typically on the side of the road at the site of the traffic stop. Common tests include requiring the driver to walk a straight line while following several instructions (the walk and turn test) and standing on one leg while extending the other leg forward (the one-legged stand test). An officer will also observe a driver’s pupils while the driver focuses on a moving object, such as the officer’s finger (known as the horizontal gaze nystagmus test, the officer is looking for involuntary twitching in the driver’s pupil, which can indicate intoxication).
Even where video of the defendant’s performance on field sobriety tests does not exist, the officer who administered the tests can testify to the jury about the defendant’s performance. While the prosecutor will attempt to convince the jury that the tests are legitimate methods of measuring the defendant’s intoxication and that the defendant’s performance indicated intoxication, the defendant’s lawyer will attempt to undermine the validity of the tests and offer explanations other than intoxication for the defendant’s allegedly poor performance on the tests.
In addition to introducing evidence of the field sobriety tests, the prosecutor will often have the officer testify about observations made of the defendant during the traffic stop and arrest. The officer may describe smelling the odor of liquor coming from the defendant’s breath, slurred speech, and watery bloodshot eyes. The prosecutor will also have the officer testify to evidence recovered from the defendant’s car, such as open beer cans or empty liquor bottles. The officer may also testify to having observed the defendant driving in a reckless manner, and the prosecutor can introduce any video taken by the officer’s patrol car camera that shows the defendant’s car swerving across lanes or otherwise driving in a way that suggests the driver may be intoxicated.
Chemical tests of a driver’s bodily fluids that show an illegal level of alcohol or drugs can be very persuasive in convincing a jury that the driver was driving while intoxicated, but chemical tests are not available to the prosecution in every case. In cases without chemical tests, a prosecutor may nonetheless be able to proceed with prosecution of the defendant for DUI because field sobriety test evidence and officer testimony exists. Whether such evidence is sufficient to prove the defendant’s guilt beyond a reasonable doubt is up to the jury (or the judge, in cases where the defendant chooses be tried without a jury).