Under what conditions can police make an arrest according to the law enforcement act?

The correct answer is based on the principle that police can lawfully make an arrest if they possess a warrant or have reasonable cause to believe that a person has committed a crime. A warrant is a legal document issued by a judge that authorizes law enforcement to arrest an individual. In cases where a warrant is not present, police must have reasonable grounds—meaning sufficient and credible information—to justify making an arrest based on observable circumstances or facts known to them at the time. This safeguard ensures that arrests are made fairly and based on evidence, preventing arbitrary detainment.

The other options present conditions that do not fully align with the legal requirements for making an arrest. Merely witnessing a crime directly does not encompass all the circumstances under which an arrest can happen, as police can act on reasonable suspicion even if they did not see the crime occur. Although it is important for suspects to be made aware of their rights during the arrest process, the knowledge of rights does not influence the legality of the arrest itself. Lastly, a report from someone about a crime does not automatically provide police with authority to arrest; they must still apply their own judgment and need reasonable cause to proceed with an arrest.