Note: Local terminology will vary, but these general classifications fall under US Supreme Court guidelines. Each stage has different requirements for establishing a basis for police or prosecutorial action. Without establishing that basis, the process is illegal and can cause a prosecution to fail under the
exclusionary rule.
1. Reasonable suspicion and traffic stop There are several situations in which the officer will come into contact with a driver, some examples are: • The officer on patrol has observed erratic, suspicious driving, or a series of traffic infractions indicating the possibility that the driver may be impaired. This is by far the most common reason for stopping a suspect. • A police officer has stopped a vehicle for a lesser traffic offense, notices the signs of intoxication, and begins the DUI investigation. • The driver has been involved in an automobile collision; the officer has responded to the scene and is conducting an investigation. • The driver has been stopped at a
sobriety checkpoint (also known as roadblocks). • The police have received a report, possibly from an anonymous citizen, that a described car has been driving erratically. The officer should verify the erratic driving before pulling the driver over. In some cases, the driver will no longer be in the vehicle. The police must have a reason to engage in a traffic stop. This typically involves either observing a traffic violation or observing behavior, such as weaving or lane departure, that would raise a "reasonable suspicion" of driving while impaired. The police must have an articulable reason for the stop, but does not need probable cause for an arrest. One exception is a roadblock (where legal). Roadblocks do not involve reasonable suspicion, but must meet particular legal standards to avoid arbitrariness while still assuring randomness. The following list of DUI symptoms, from a publication issued by the National Highway Traffic Safety Administration (DOT HS-805-711), is widely used in training officers to detect drunk drivers. After each symptom is a percentage figure which, according to NHTSA, indicates the statistical chances through research that a driver is over the legal limit. During the traffic stop, the police will attempt to obtain sufficient evidence to support "probable cause". This includes asking questions, and requesting further evidence or confession. The officer will typically approach the driver's window and ask some preliminary questions. During this phase of the stop, the officer will note if they detect any of the following indicators of intoxication: • Odor of an alcoholic beverage on the driver's breath or in the car generally • Slurred speech in response to the questioning • Watery, blood shot, or reddish eyes • Flushed face • Droopy eyelids • Difficulty in understanding and responding intelligently to question • Fumbling with his or her driver's license and registration • The plain-view presence of containers of alcoholic beverages in the vehicle • Admission of consumption of alcoholic beverage If the officer observes enough evidence to have a "
Reasonable Suspicion" to legally justify a further detention and investigation, they will ask the driver to step out of the vehicle.
2. Probable cause "Probable cause" is established by obtaining evidence from the police encounter sufficient to meet the "probable cause" standard for arrest. "Probable cause" is not necessarily sufficient to obtain a conviction, but is a prerequisite for arrest. Specifically, in US law, an officer must have
probable cause for arrest in order to invoke the
implied consent requirements. In order to sustain a conviction based on evidential tests,
probable cause must be shown (or the suspect must volunteer to take the evidential test without implied consent requirements being invoked). Police are not obliged to advise the suspect that participation in a FST or other pre-arrest procedures is voluntary. In contrast, formal evidentiary tests given under implied consent requirements are considered mandatory. :2.
Confession of having consumed alcohol in the recent past.
Relevant examples of confessions: ::* "I had a glass of wine." ::* "I was at a friend's party." ::* "I was at the Stone Balloon." ::The confession is the easiest way to establish "probable cause", and police know that
social convention encourages people to respond to police questions.
While it is inadvisable to lie to police, the suspect has the option to "respectfully decline" to answer questions. ::The suspect is typically not given
Miranda warnings at this time because the encounter legally has not gone from "investigatory" to "accusatory", and because the police want the suspect to believe the questions are not being made to gather "probable cause" evidence. At this point, the suspect is not required to provide more than identification and vehicle information. :3. Documented test results, such as ::* Preliminary breath test (PBT) evidence ::* Test results from
field sobriety tests Field sobriety tests One of the most controversial aspects of a DUI stop is the
field sobriety test (FSTs). The
National Highway Traffic Safety Administration (NHTSA) has developed a model system for managing Standardized Field Sobriety Test (SFST) training and published numerous training manuals associated with FSTs. FSTs and SFSTs are promoted as determining "whether a subject is impaired", but FST tests are widely regarded having, as their primary purpose, establishing tangible evidence of "
probable cause for arrest". In all US jurisdictions, participation in a
Field Sobriety Test (FST) is voluntary, and not required under
implied consent laws. but is not considered to be a refusal under the general "implied consent" law. In some states, the state may present evidence of refusal to take a field sobriety test in court, although this is of questionable probative value in a drunk driving prosecution. Different requirements apply in many states to drivers under DUI probation, in which case participation in a preliminary breath test (PBT) may be a condition of probation, and for commercial drivers under "drug screening" requirements. Some US states, notably California, have statutes on the books penalizing PBT refusal for drivers under 21; however the
Constitutionality of those statutes has not been tested. (As a practical matter, most criminal lawyers advise not engaging in discussion or "justifying" a refusal with the police.)
3. Arrest (including invoking the implied consent law) Probable cause for arrest If the officer has sufficient probable cause that the suspect has been driving under the influence of alcohol, they will make the arrest,
handcuff the suspect and transport them to the police station. En route, the officer may advise them of their legal
implied consent obligation to submit to an evidentiary chemical test of blood, breath or possibly urine depending on the jurisdiction. Laws relating to what exactly constitutes probable cause vary from state to state. In California it is a refutable presumption that a person with a BAC of 0.08% or higher is driving under the influence. However, section 23610(a)(2) of the
California Vehicle Code states that driving with a BAC between 0.05% and 0.08% "shall not give rise to any presumption that the person was or was not under the influence of an alcoholic beverage".
Chemical test An arrestee will be offered a chemical test of breath, blood or, much less frequently, urine. Breath test results are usually available immediately; urine and blood samples are sent to a
lab for later analysis to determine the BAC or possible presence of drugs. Some states sought to impose criminal punishment for a refusal to submit to a chemical test of their breath or blood; however, in
Birchfield v. North Dakota, the
United States Supreme Court visited the issue of whether states can criminalize a refusal to submit to a chemical test. The United States Supreme Court decided that states may criminalize a refusal to submit to a breath test; but not a refusal to submit to a blood test absent a McNeely warrant, named after
Missouri v. McNeely (2013). This was a case decided by United States Supreme Court, on appeal from the Supreme Court of Missouri, regarding exceptions to the Fourth Amendment to the United States Constitution under exigent circumstances. The United States Supreme Court ruled that police must generally obtain a warrant before subjecting a drunken-driving suspect to a blood test, and that the natural metabolism of blood alcohol does not establish a per se exigency that would justify a blood draw without consent. Regarding blood tests, some commentators, such as Brown University's Jacob Appel, have criticized the role of medical personnel in this process. According to Appel, "If physicians acquiesce today in the removal of a resistant patient's blood, soon they may be called upon to pump the contents of an unwilling patient's stomach or even to perform involuntary surgery to retrieve an evidentiary bullet." While chemical tests are used to determine the driver's BAC, they do not determine the driver's level of impairment. However, state laws usually provide for a rebuttable legal presumption of intoxication at a BAC of 0.08% or higher (see
blood alcohol test assumptions).
4. Criminal charge, and "civil law" sanctions Booking and charging If it is determined after arrest that the person's BAC is not at or above the legal limit of 0.08%, they will probably be released without any charges. One may, however, still be charged with driving under the influence of alcohol on the basis of driving symptoms, observed impairment, admissions or performance on the field sobriety tests. And if there is suspicion of drug usage, a blood or urine test is likely, or at least the testimony of a specially trained officer called a
Drug Recognition Expert (DRE). Assuming sufficient evidence of impaired driving from drugs, the arrested may face charges of driving under the influence of drugs or the combined influence of alcohol and drugs. Most of the time, the driver will either be kept in a holding cell (sometimes referred to as the "
drunk tank") until they are deemed sober enough to be released on
bail or on his "own
recognizance" (OR). A date to appear in court for an
arraignment will be given to them. If they cannot make bail or is not granted OR, they will be kept in jail to wait for the arraignment on
remand. ==Cost of an impaired driving charge==