What is required to establish reasonable cause during a DWI stop?

To establish reasonable cause during a DWI stop, probable cause is necessary. This means that law enforcement must have a set of facts or circumstances that would lead a reasonable person to believe that a driver is operating a vehicle while under the influence of alcohol or drugs. Probable cause is a higher standard than just a mere suspicion; it often involves specific observations such as erratic driving, slurred speech, or the smell of alcohol.

The requirement for probable cause is rooted in protecting individual rights against arbitrary detention and arrest. It ensures that law enforcement has enough justification to stop a vehicle and investigate further, such as administering field sobriety tests. Without establishing probable cause, subsequent actions like arresting the driver or conducting breath tests could be deemed unlawful.

The other options do not meet the legal threshold required for initiating a DWI stop. Personal belief, while it may reflect an officer's intuition, does not provide the legal standard necessary for establishing reasonable cause. Witness testimony can support an investigation but does not alone justify the stop. Video evidence can be valuable in corroborating an incident but, like witness testimony, cannot establish reasonable cause on its own without additional supporting observations.