Which of the following is an example of exigent circumstances?

Exigent circumstances arise when there is an urgent need for law enforcement to act in a situation that requires immediate action to prevent harm, destruction of evidence, or the escape of a suspect. In this context, when an officer sees someone commit a crime, it constitutes exigent circumstances because it compels the officer to respond immediately to address the crime in progress. The immediacy of witnessing a crime allows the officer to take necessary actions without a warrant, as waiting for a warrant could result in the loss of evidence or allow the suspect to flee.

In contrast, a routine traffic stop does not involve any exigency; it is typically planned and follows standard procedures. Waiting for a warrant does not align with the concept of exigency, as it implies a delay that is inappropriate in urgent situations. Conducting a search of a home on a whim lacks legal justification and does not meet the criteria for exigent circumstances, as there would be no immediate need or threat that necessitates such action.