What must law enforcement demonstrate to establish probable cause for a DUI arrest?

To establish probable cause for a DUI arrest, law enforcement must demonstrate signs of impairment, such as erratic driving or behavior. This means that officers observe actions or indications that suggest a driver may be under the influence of alcohol or drugs. Erratic driving can include weaving, swerving, speeding, or failing to obey traffic signals, which can all signal that the driver is impaired.

The presence of these signs provides officers with a reasonable basis to suspect that a driver is not operating the vehicle safely due to intoxication. This foundational evidence is crucial for justifying further investigation, such as pulling the driver over and potentially conducting field sobriety tests or breathalyzer tests.

While other factors might contribute to or support an officer's assessment during a traffic stop, they do not constitute sufficient probable cause on their own for a DUI arrest. For example, good driving behavior, witness testimony alone, or a vehicle's registration status do not directly indicate whether the driver is impaired. Hence, the correct choice focuses on the signs of impairment that are necessary for establishing probable cause.