A more thorough explanation:

Definition: Mild exigency refers to a situation where a law enforcement officer can depart from the knock-and-announce rule. This rule requires the police to knock on the door and announce their identity, authority, and purpose before entering a residence to execute an arrest or search warrant. Mild exigency justifies the officer's departure from this rule, such as when there is a likelihood that the building's occupants will try to escape, resist arrest, or destroy evidence.

Example: If the police have a search warrant for a house where they suspect illegal drugs are being sold, they must knock on the door and announce themselves before entering. However, if they hear noises inside the house that suggest the occupants are trying to destroy evidence, they can depart from the knock-and-announce rule and enter the house without warning.

This example illustrates how mild exigency justifies a departure from the knock-and-announce rule. The police have a legitimate reason to believe that the occupants of the house are destroying evidence, which could harm the investigation. Therefore, they can enter the house without warning to prevent this from happening.