Which of the following is a requirement for a legal arrest?

For an arrest to be considered legal, it is essential that probable cause is established. Probable cause means that the law enforcement officer has sufficient reason, based on facts and circumstances, to believe that a crime has been committed or that a specific individual has committed a crime. This is a fundamental principle in criminal law that protects individuals from unlawful detainment or arrest without sufficient evidence.

The necessity for probable cause aligns with constitutional protections, specifically the Fourth Amendment, which guards against unreasonable searches and seizures. If an arrest is made without probable cause, it could be deemed illegal, potentially resulting in the exclusion of any evidence obtained during the arrest from being used in court.

Other options, such as the presence of witnesses, officer discretion, and valid identification, do not inherently constitute legal grounds for an arrest. While witnesses can be helpful in corroborating an officer's observations, their presence is not a legal requirement. Officer discretion plays a role in enforcement decisions, but it cannot replace the need for probable cause, as discretion alone does not justify making an arrest. Lastly, while valid identification may assist in the identification process, it is not a necessary component for establishing that a legal arrest has taken place.