What must a police officer do before making an arrest?

The correct concept is that a police officer must inform the individual of the arrest, as this is a fundamental requirement of due process each time an arrest is made. Informing the individual allows them to understand the nature of the arrest, including the charges being brought against them, and their rights, which is vital to ensuring legal fairness and transparency in law enforcement.

When a police officer arrests someone, it is also essential to communicate why the arrest is happening to uphold the integrity of the law and protect the rights of the individual. This action aligns with the principles of accountability and lawful process that govern police conduct.

In terms of the other choices, while determining the identity of the individual is a critical part of the arrest process, it does not represent the core requirement before making an arrest. Securing a warrant, though necessary in many cases, is not always mandatory—officers can make arrests without a warrant in certain circumstances, such as when a crime is witnessed firsthand. Verifying that a crime has been committed is crucial as well, but it is typically part of the overall process of establishing probable cause rather than a separate step that must happen before an arrest.