LAS VEGAS DUI POLICE EVIDENCE
The evidence gathered in a drunk driving case can be placed into five categories. The first is driving symptoms. Unless an obvious incident such as an accident occurs, driving symptoms are what police officers typically first notice. These symptoms may include, but are not limited to, weaving, lane straddling, or erratic driving. Twenty patterns are recognized by the National Highway Traffic Safety Administration that are common indicators of intoxication. Surprisingly, speeding is not considered one of the patterns. Excessive speeding requires coordination, quick judgment, and fast reflexes.
The second category of evidence deals with the individual’s behavior and appearance. Examples of evidence in this category includes: odor of alcohol on suspect’s breath, bloodshot eyes, slurred speech, flushed face, fumbling items in one’s hands, inability to keep balance, and difficulty following directions. Some of these examples, such as the alcohol odor or bloodshot eyes, are encountered by the arresting officer so often that they will include the items in arrest reports regardless of if they are actually present.
The third category of evidence consists of field sobriety tests. These tests include the following:
- Walk-and-turn
- Touch-the-nose
- One-leg-stand
- Modified position of attention (also known as the Rhomberg test)
- Alphabet recitation
- Horizontal gaze nystagmus (following an object such as a pen or finger from side-to-side with your eyes)
- Fingers-to-thumb
- Hand pat
It is generally believed that any or all of these tests are required; however, you have the right to refuse to take any of them without any legal ramifications. Federal studies have indicated that only three of these tests (walk-and-turn, one-leg-stand, and nystagmus) are proven to effectively detect intoxication. The others listed are, based on the study, unreliable and hence have been disapproved. In response, a standardized set of these three tests have been recommended and are being adopted by police agencies across the country; this recommendation has been disregarded by many officers in California.
A larger number of police agencies are beginning to use a roadside breath-testing device as an added field sobriety test. Know as a “PAS” (Preliminary Alcohol Screening) or “EPAS” (Evidential Portable Alcohol System), these hand held units are intended to give a preliminary estimate of the suspect’s blood-alcohol concentration. The units are still in early development with regards to their technology and are not fully reliable. Their intent is to only be used as an aid to the officer in determining if a DUI is present after other tests have been administered. It must be noted that submission to a PAS test is not legally required. Again, disregarding the original intent of the units, many judges have allowed the results to be used as evidence in court.
The fourth category consists of incriminating statements, regardless if made spontaneously or when answering questions. Once again, the suspect is not required to answer any questions at any time. Since the Miranda warning is not required to be given until after the arrest, the officer is allowed to ask any questions during his investigation. However, a refusal to submit to a chemical test may be interpreted as an incriminating statement.
The last category of evidence consists of the chemical test. In Nevada, this includes the choice of breath or blood tests. The machines used in these tests are susceptible to a number of flaws and as such are not reliably accurate. First, the computer used by the machines makes assumptions; such as the person is of average physiology and metabolism. Second, if the suspect burps or belches during the test, the machine will give an inaccurate reading for approximately 15 minutes following the bodily function. Finally, the machine does not necessarily measure alcohol. The machine actually measures the methyl group within the alcohol compound, and there are thousands of compounds that are in this group; many of these have been documented on the human breath.
Blood analysis is considerably more accurate, although possible problems exist there as well, such as fermentation of the sample, coagulation, chain of custody and lack of sterilization.