Field Sobriety Tests
Historically, guilt was established by observed driving symptoms, such as weaving; administering field sobriety tests, such as a walking a straight line heel-to-toe or standing on one leg for 30 seconds; and the arresting officer’s subjective opinion of impairment. The officer must correctly perform the Field Sobriety Tests that are approved by the National Highway Transportation Safety Administration (NHTSA). The US Department of Transportation explains the Field Sobriety Test as, “a battery of three tests administered and evaluated in a standardized manner to obtain validated indicators of impairment and establish probable cause for arrest.” Starting with the introduction in Norway in 1936 of the world’s first per se law which made it an offense to drive with more than a specified amount of alcohol in the body, objective chemical tests have gradually supplanted the earlier purely judgmental ones. Limits for chemical tests are specific for blood alcohol concentration or concentration of alcohol in breath.
The Miranda warning (also referred to as Miranda rights) is a warning given by police in the United States to criminal suspects in police custody (or in a custodial interrogation) before they are interrogated to preserve the admissibility of their statements against them in criminal proceedings. In other words, a Miranda warning is a prophylactic criminal procedure rule that law enforcement is required to administer in order to protect an individual who is in custody and subject to direct questioning or its functional equivalent from a violation of his or her Fifth Amendment right against compelled self-incrimination. In Miranda v. Arizona, the Supreme Court held that the admission of elicited incriminating statement by a suspect not informed of these rights violates the Fifth Amendment privilege against self-incrimination and the Sixth Amendment right to counsel. Thus, if law enforcement officials decline to offer a Miranda warning to an individual in their custody, they may still interrogate that person and act upon the knowledge gained, but may not use that person’s statements to incriminate him or her in a criminal trial.
In Berghuis v. Thompkins, the Court held that, if a suspect waives this right and interrogation begins, the right to halt further interrogation by the police must be exercised explicitly, by revoking the prior waiver.