Driving Under the Influence vs. Actual Physical Control
Under Oklahoma law, it is unlawful to operate a motor vehicle on the public roadways while under the influence of an intoxicating substance. The legal term is Driving under the Influence. It is also illegal to be under the influence in a vehicle which is parked if the person has the means to operate the vehicle, typically the keys, and the vehicle is operational, meaning that the vehicle does not have a mechanical issue rendering the vehicle unable to be driven. The legal term for this is Actual Physical Control. Under the law, Actual Physical Control is treated identically to Driving under the Influence. The methodology to determine intoxication, and the possible punishment are the same under each offense. In Oklahoma a first offense of Driving under the Influence is punishable as a misdemeanor with a punishment range of ten days to a year in jail, and a fine of up to $1,000. A second offense within ten years is punishable as a felony, with a possible punishment of one to five years in the custody of the Department of Corrections and a fine of up to $2,500. Offenses subsequent to a second offense have increasing possible terms of imprisonment.
The legal threshhold used in determining when a person is “under the influence” is when that person has: a blood or breath alcohol concentration of 0.08% or more within two hours of arrest; or has any amount of a Schedule 1 chemical or controlled substance in their blood, saliva, urine or any other bodily fluid. There are well-established rules and guidelines that must be followed by an arresting agency when investigating and filing a charge of Driving under the Influence. If these procedures are not performed correctly, the evidence gathered through improper means will be ruled inadmissible and not be allowed to be used in the case against you. The most crucial areas of inquiry are the officer’s performance of the Standardized Field Sobriety Tests (or SFST’s), and the methods used in examining breath or blood samples to determine the presence of threshold amounts of substances.
In the late 1970’s, the National Highway Traffic Safety Administration (NHTSA) developed a battery of tests designed to standardize the methods used to determine if a person is under the influence, primarily of alcohol. In 1981, law enforcement officers from across the United States began using NHTSA's Standardized Field Sobriety Test (SFST) battery to help make arrest decisions in suspected Driving under the Influence cases.
1) Horizontal Gaze Nystagmus (HGN) test: Horizontal gaze nystagmus is an involuntary jerking of the eyeball which occurs naturally as the eyes gaze to the side. Under normal circumstances, nystagmus occurs when the eyes are rotated at high peripheral angles.
However, when a person is impaired by alcohol, nystagmus is exaggerated and may occur at lesser angles. An impaired person will also often have difficulty smoothly tracking a moving object. In the HGN test, the officer observes the eyes of a suspect as the suspect follows a slowly moving object such as a pen or small flashlight, horizontally with his eyes. The examiner looks for three indicators of impairment in each eye: if the eye cannot follow a moving object smoothly, if jerking is distinct when the eye is at maximum deviation, and if the angle of onset of jerking is within 45 degrees of center. The subject is likely to have a BAC of 0.10 or greater if, between the two eyes, four or more clues appear. NHTSA research indicates that this test allows proper classification of approximately 77 percent of subjects. HGN may also indicate consumption of seizure medications, phencyclidine, a variety of inhalants, barbiturates, and other depressants.
Divided Attention Testing
The Walk-and-Turn test and the One-leg Stand test are “divided attention” tests which are easily performed by most sober people. They require a suspect to listen to and follow instructions while performing simple physical movements. Impaired people have difficulty with tasks requiring their attention to be divided between simple physical and mental exercises.
2) Walk-and-Turn test: the subject is directed to take nine steps, heel-to-toe, along a straight line. After taking the steps, the suspect must turn on one foot and return in the same manner in the opposite direction. The examiner looks for seven indicators of impairment: if the suspect cannot keep balance while listening to the instructions, begins before the instructions are finished, stops while walking to regain balance, does not touch heel-to-toe, uses arms to balance, loses balance while turning, or takes an incorrect number of steps. NHTSA research indicates that 68 percent of individuals who exhibit two or more indicators in the performance of the test will have a BAC of 0.10 or greater.
3) One-leg Stand test: the subject is instructed to stand with one foot approximately six inches off the ground and count aloud by ones beginning with one until told to put the foot down. The officer times the subject for about 30 seconds. The officer looks for four indicators of impairment including: swaying while balancing, using arms to balance, hopping to maintain balance, and putting the foot down.
NHTSA research indicates that 65 percent of individuals who exhibit two or more such indicators in the performance of the test will have a BAC of 0.10 of greater.¹
There are several methods used to provide evidence of intoxication from alcohol and other sources. Including:
A breathalyzer is a device for estimating blood alcohol content (BAC) from a breath sample. Breath analyzers do not directly measure blood alcohol content or concentration, which requires the analysis of a blood sample. Instead, they estimate BAC indirectly by measuring the amount of alcohol in one's breath. Two breathalyzer technologies are most prevalent. Desktop analyzers generally use infrared spectrophotometer technology, electrochemical fuel cell technology, or a combination of the two. Hand-held field testing devices are generally based on electrochemical platinum fuel cell analysis and, depending upon jurisdiction, may be used by officers in the field as a form of "field sobriety test" commonly called PBT (preliminary breath test) or PAS (preliminary alcohol screening) or as evidential devices in POA (point of arrest) testing. ²
The breath alcohol content reading is used in criminal prosecutions in two ways. The operator of a vehicle whose reading indicates a BAC over the legal limit for driving will be charged with having committed an illegal per se offense: that is, it is automatically illegal throughout the United States to drive a vehicle with a Breath Alcohol Concentration (BrAC) of 0.08% or higher.
Infrared instruments are also known as "evidentiary breath testers" and generally produce court-admissible results. Other instruments, usually hand held in design, are known as "preliminary breath testers" (PBT), and their results, while valuable to an officer attempting to establish probable cause for a drunk driving arrest, are generally not admissible in court.
² Wikipedia : Breathalyzer
Common Breathalyzer Errors
1) Calibration Many handheld breath analyzers sold to consumers use a silicon oxide sensor (also called a semiconductor sensor) to determine the blood alcohol concentration. These sensors are far more prone to contamination and interference from substances other than breath alcohol. The sensors require recalibration or replacement every six months.
Higher end personal breath analyzers and professional-use breath alcohol testers use platinum fuel cell sensors. These too require recalibration but at less frequent intervals than semiconductor devices, usually once a year. Calibration is the process of checking and adjusting the internal settings of a breath analyzer by comparing and adjusting its test results to a known alcohol standard. Law enforcement breath analyzers need to be meticulously maintained and re-calibrated frequently to ensure accuracy.
2) Non-specific Analysis
One major problem with older breath analyzers is non-specificity: the machines identify not only the ethyl alcohol (or ethanol) found in alcoholic beverages but also other substances similar in molecular structure or reactivity.
3) Interfering Compounds
Some natural and volatile interfering compounds do exist, however. For example, the National Highway Traffic Safety Administration (NHTSA) has found that dieters and diabetics may have acetone levels hundreds or even thousands of times higher than those in others. Acetone is one of the many substances that can be falsely identified as ethyl alcohol by some breath machines. However, fuel cell based systems are non-responsive to substances like acetone.Substances in the environment can also lead to false BAC readings. For example, methyl tert-butyl ether (MTBE), a common gasoline additive, has been alleged anecdotally to cause false positives in persons exposed to it. Tests have shown this to be true for older machines; however, newer machines detect this interference and compensate for it. Any number of other products found in the environment or workplace can also cause erroneous BAC results. These include compounds found in lacquer, paint remover, celluloid, gasoline, and cleaning fluids, especially ethers, alcohols, and other volatile compounds.
4) Mouth Alcohol
One of the most common causes of falsely high breath analyzer readings is the existence of mouth alcohol. In analyzing a subject's breath sample, the breath analyzer's internal computer is making the assumption that the alcohol in the breath sample came from alveolar air—that is, air exhaled from deep within the lungs.
However, alcohol may have come from the mouth, throat or stomach for a number of reasons. To help guard against mouth-alcohol contamination, certified breath-test operators are trained to observe a test subject carefully for at least 15–20 minutes before administering the test. The problem with mouth alcohol being analyzed by the breath analyzer is that it was not absorbed through the stomach and intestines and passed through the blood to the lungs. In other words, the machine's computer is mistakenly applying the partition ratio (see above) and multiplying the result. Consequently, a very tiny amount of alcohol from the mouth, throat or stomach can have a significant impact on the breath-alcohol reading.
A blood alcohol test measures the amount of alcohol (ethanol) in your body. Alcohol is quickly absorbed into the blood and can be measured within minutes of having an alcoholic drink. The amount of alcohol in the blood reaches its highest level about an hour after drinking. But food in the stomach may increase the amount of time it takes for the blood alcohol to reach its highest level. About 90% of alcohol is broken down in the liver. The rest of it is passed out of the body in urine and your exhaled breath.³ Blood tests taken at a hospital or police station are the most accurate chemical sobriety evaluations used to determine the blood alcohol level of a subject.
They are also, unfortunately, the least convenient and most expensive. Considered an intrusive method, a blood alcohol test can quickly determine the amount of alcohol in the blood at the time the sample is taken. Since the body continues to break down alcohol at a steady rate after drinking, the time that passes between drinking and collecting the blood sample will affect the results. Blood alcohol tests are very accurate in determining BAC levels, but in some cases, the results may be misleading. These cases may involve people with diabetes or high blood ketones or people taking cough medicines or herbal supplements. However, the most susceptible variable in blood testing for alcohol levels is determined by the actual methodology of the blood drawing.
First and perhaps most obvious, the sample is at risk of alteration by an alcohol swab before the needle is inserted. As the needle is inserted, the alcohol on the surface of the skin can actually contaminate the sample by increasing the overall amount of alcohol found in the blood .4
³ WebMD 4 DUI Foundation
Blood Test for Drug Detection
When it is suspected that a person is under the influence of an intoxicating substance, blood analysis may be used by law enforcement. Drugs are metabolized and eliminated from the body at different rates, depending on the type of drug and on other factors including the person’s metabolism. Estimated times for drugs to remain present in a blood sample are as follows:
Alcohol: 3 to 10 hours Amphetamines: 24 to 48 hours Barbiturates: up to 6 weeks Benzodiazepines: up to 6 weeks with high level use Cocaine: 2 to 4 days; up to 10 to 22 days with heavy use Codeine: 1 to 2 days Heroin: 1 to 2 days Hydromorphone: 1 to 2 days Methadone: 2 to 3 days Morphine: 1 to 2 days Phencyclidine (PCP): 1 to 8 days Propoxyphene: 6 to 48 hours Tetrahydrocannabinol (THC): 6 to 11 weeks with heavy use
Given the costs associated with blood tests, law enforcement agencies are turning to saliva tests to determine narcotic intoxication. The process uses a swab that looks similar to a toothbrush, with a pad that collects the saliva from the donor's mouth. The swab is placed between a person's gum and lower cheek for a couple of minutes before being removed and placed in a vial to send for testing.
The mouth swab drug test detection period is essentially similar to the period of detection through blood samples. Drug detection periods depend on the type of drug consumed, the quantity consumed and the recurrence of consumption. Regular users may have traces of drugs in their saliva even if they have not used that particular drug for the duration that it takes to wear off. Some drugs wear off within 24 hours of consumption while others may take 5 to 7 days. It remains to be seen how widespread this method will become in testing drivers for intoxication.
Drug Recognition Experts
Often the behavior of a suspect is abnormal for alcohol impairment alone, or field or breath tests indicate that the suspect's BAC is lower than the level of impairment suggests. Either of these observations is common when encountering poly-drug users. Most jurisdictions have laws that prohibit DUI by alcohol, drugs, or a combination thereof.
Drug Recognition Experts (DREs) are officers who have been specifically trained to recognize the effects of drug impairment. The DRE examines such suspects and makes trained observations to determine whether to request a blood or urine test, and to guide the laboratory technician toward what general categories of drugs to look for in analysis of the sample. The DRE's examination also provides evidence of observable drug effects to help confirm the lab analysis. 5