What must an officer have to stop a vehicle according to Step 1?

To stop a vehicle, an officer must have reasonable articulable suspicion. This standard allows officers to take action based on specific facts or circumstances that would lead a reasonable officer to believe that a crime may be occurring or is about to occur. This threshold is lower than probable cause, which is required for making arrests or conducting searches.

In the context of traffic stops, reasonable articulable suspicion could arise from observing erratic driving behavior, such as swerving or speeding, which may suggest that a driver is impaired or otherwise engaged in illegal activity. The ability to stop a vehicle for such suspicion is crucial for public safety as it allows law enforcement to intervene before potential harm occurs.

The other options, such as a warrant for arrest, are not necessary for an initial stop. A warrant is required for making an arrest after a stop has occurred or when entering a property. Probable cause of drunkenness is a higher standard that comes into play once an officer has stopped a vehicle and is conducting further investigation, such as administering sobriety tests. A witness statement may support an officer's suspicion but is not a necessary condition for making the initial stop of a vehicle.