The starting point for any discussion of the applicable law for an Alabama law enforcement officer to stop and detain and subsequently arrest an individual pursuant to a traffic stop is the U.S. Supreme Court's leading decision of Terry v. Ohio, 392 U.S. 1 (1968). Terry established the rule that a police seizure need not amount to a full arrest in order to subject the seizure to the Constitutional requirements of the Fourth Amendment, and that a seizure of limited duration and limited scope may be reasonable under Fourth Amendment analysis in the absence of traditional probable cause, provided there was 'reasonable suspicion' to believe the person being stopped and detained had committed or was about to commit an illegal act.

A corresponding state statute on the same subject is found in the Code of Alabama, 1975, section 15-5-30, which authorizes an Alabama law enforcement officer to "stop any person abroad in a public place who he reasonably suspects is committing, has committed or is about to commit a felony or other public offense and may demand of him his name, address and an explanation of his actions."

Taken together, both the decisional law of the state and federal courts and the statutory law of the state of Alabama authorize a law enforcement officer to stop, detain, question, and investigate any person "reasonably suspected" of engaging in criminal activity, including traffic violations, but subject to Constitutionally imposed restraints on the officer's conduct.

Was the traffic stop a seizure? The starting point to determine the lawfulness of any police-citizen encounter in context of the Fourth Amendment is the initial determination of whether the interaction between the police officer and the citizen was voluntary, consensual and non-coercive and thus outside the scope of the Fourth Amendment, or was police-citizen encounter a product of law enforcement authority and show of force, thereby requiring law enforcement compliance with the Constitutional standard of reasonableness.

It has long been held that a police officer, like any citizen, can approach any person in a public area and strike up a conversation, even a conversation concerning the person's participation in or knowledge of criminal activity, without requiring the slightest degree of suspicion on part of the officer, provided the questioned person is free not to respond to the officer's questioning and is free to leave.

However, when a law enforcement officer employs what is termed "show of force" or "show of authority" consistent with his vested law enforcement powers, such use of authority to stop and detain a citizen crosses the boundary of the voluntary and consensual encounter and moves into the realm of the Fourth Amendment.

The regulation of movement of vehicles on the highway by law enforcement is continually scrutinized under Fourth Amendment standards. The police use of emergency lights, police siren, or other indicia of authority to direct a motorist to pull over and come to a stop, which may include simply pointing to a motorist and giving direction by hand signal for the motorist to stop, reviewing courts have consistently held such police actions squarely falling within the concept of "show of force."

There are several overlapping sections of the Code of Alabama requiring a motorist to comply with law enforcement authority directing the motorist to yield to law enforcement or to come to a complete stop. Failure to comply subjects the motorist to the additional charge of "attempting to elude." The recently revised "attempting to elude" statute carries heavy penalties, including possible imprisonment, a substantial fine, and the imposition of mandatory driver license suspension if convicted. Consistent with prior opinions of the Supreme Court, any show of force by a law enforcement officer, to include the use of police equipment to indicate to a motorist to stop, even a law enforcement officer's hand gesture to a motorist to pull over, places the burden of Constitutional reasonableness on the government. Such actions are customarily termed a "seizure" under the Fourth Amendment.

The Supreme Court has frequently asserted that the "core," "basic purpose," and "central concern" of the Fourth Amendment is the protection of liberty and privacy against arbitrary government interference. The 11th U.S. Circuit Court of Appeals flatly stated: "The Fourth Amendment protects individuals from unreasonable search and seizure." Seizure of persons and property conducted without judicial warrant are presumptively invalid, and the burden of proving the lawfulness of the seizure shifts to the prosecution. It is, therefore, the duty of the prosecuting authorities to establish to the trial court that the officer's actions at the time the seizure was made were in conformity with the Fourth Amendment.

The current leading case interpreting police traffic stops within the Constitutional framework is Whren v. United States where a unanimous court held that the temporary detention of a motorist upon probable cause to believe that the motorist has violated the traffic law does not violate the Fourth Amendment's prohibition against unreasonable seizures, even if the officer would not have stopped the motorist absent some additional objective.

Whren was a significant Fourth Amendment decision as it established a national standard for all courts, state and federal, to use in resolving the then on-going judicial conflict concerning the "objective test" standard based solely on the lawfulness of stop as compared to a more nuanced determination of the officer's "subjective intent." Under the "subjective intent" test, the reviewing court would analyze and determine whether a traffic stop, ostensibly based on violation of the state's traffic code, could be used to gain evidence of other crimes or to acquire information from the driver unrelated to the traffic stop itself.

Prior to the Whren decision, such police-citizen traffic stop encounters were commonly termed "pre-textual traffic stops" and depending on the court conducting the review, may or may not, have passed judicial scrutiny. Since Whren, all courts now utilize the fact-based inquiry of whether or not an actual traffic violation occurred. If an actual, bona fide traffic violation occurred, such violation would permit any duly sworn and appointed law enforcement officer to exercise his or her authority and conduct a traffic stop. The officer's subjective intent is thus irrelevant under the Whren standard.

The key to the Whren holding is the acknowledgement and recognition by the Court that any non-voluntary police-citizen encounter implicates the Fourth Amendment. The Court stated the nexus of the issue in this manner:

"The Fourth Amendment guarantees "[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable seizures." Temporary detention of individuals during the stop of an automobile detained by the police, even if only for a brief period and for a limited purpose, constitutes a "seizure" of "persons" within the meaning of this provision. [Citations omitted].

An automobile stop is thus subject to the constitutional imperative that it not be "unreasonable" under the circumstances. As a general matter, the decision to stop an automobile is reasonable where the police have probable cause to believe that a traffic violation has occurred." Whren, 116 S. Ct. at 1772.

Under Whren and all subsequent judicial analysis of police traffic stops, the key question is whether the officer possessed probable cause of a violation of the law at the time the use of force or show of authority was exercised. In other words, had an actual, or reasonably suspected, violation of the law occurred in the officer's presence to authorize the police to lawfully exercise a show of force and to seize the individual?

Whren an extension of the Terry doctrine: Shortly after Terry was decided, traffic stops were included under the Terry standard for analysis in both the state and federal courts. A traffic stop by use of police authority fell within the scope of Terry's parameters. As example, in Berkemer v. McCarty, the Supreme Court held the roadside questioning of a motorist detained pursuant to a routine traffic stop did not amount to a custodial interrogation and stated "the usual traffic stop is more analogous to a so-called 'Terry stop' than a formal arrest."

The core concept to any Terry based police-citizen encounter is that of objective reasonableness. More specifically, when dealing with automobiles on the highways, the analysis must be based on whether "the police have probable cause to believe that a traffic violation has occurred." Without the key factor of "probable cause" that a traffic violation has occurred, police action to stop a vehicle is an invalid exercise of police authority and clearly falls into the area of an unlawful detention.