What indicates that an officer has probable cause in a DUI case?

In a DUI case, probable cause refers to a reasonable belief that an individual is committing or has committed a crime, in this case, driving under the influence of alcohol or drugs. The correct choice highlights that an officer's belief in the accused's impairment while driving is a key indicator of probable cause. This belief can stem from observable behaviors, such as swerving, erratic driving, or other signs of intoxication demonstrated by the driver.

When an officer observes these behaviors, it provides them with a legal basis to initiate a traffic stop and investigate further. The belief in impairment is specifically tied to the standards of DUI enforcement, as it aligns with the necessity for the officer to act upon concrete observations rather than mere assumptions.

The other choices do not provide sufficient grounds for establishing probable cause. Personal belief without observable evidence, a minor traffic violation that does not indicate impairment, and time of day do not sufficiently support the need for further investigation into a driver's sobriety.