Within the context of driving under the influence cases, there exists many legal concepts unique to the area, among those are the somewhat mysterious legal terminology of "probable cause" and how that differs from reasonable suspicion. Thanks to Kern County DUI Attorneys in Shafter and Taft CA we have a great primer on the distinction between the two terms.
The facts and observations divulged during an investigatory detention may lead to probable cause to arrest the person detained for a DUI case. However, the officer must possess facts sufficient to support crossing the threshold between mere reasonable suspicion to detain and question, and full probable cause to arrest, before the latter action may be taken. If the investigating officer does not yet possess facts sufficient to create probable cause to believe the detainee has committed a crime, yet restrains the liberty of the detainee in a manner consistent with a formal arrest, the detention, even if initially lawful, becomes illegal. For example, transporting a DUI suspect involuntarily to a stationhouse for further questioning, without probable cause to link him with a crime such as driving under the influence, violates the detainees Fourth Amendment rights. This more intrusive step in the investigatory process requires probable cause and cannot be justified on reasonable suspicion alone. Courts look to the extent of the restriction on an individuals freedom and movement to determine if the restraint is more consistent with a detention, or a full-blown arrest. For example, although the use of handcuffs on a suspect is a hallmark of a formal arrest and is generally considered a watershed, where a temporary detention becomes an arrest, a suspect nonetheless may be handcuffed or similarly restrained during a temporary detention, if the circumstances justify it.