Final answer:
A police officer requires probable cause to make an arrest, which is a reasonable belief that a person has committed a crime, based on evidence and circumstances. This standard goes beyond personal judgment, the crime's severity, time of day, or experience level and is guided by legal procedures and the officer's informed observations.
Step-by-step explanation:
The amount of justification needed for a police officer to make an arrest is not simply based on an officer's personal judgment, the severity of the alleged crime, the time of day, or the officer's experience level. Instead, the legal standard requires probable cause: a reasonable amount of suspicion, supported by circumstances sufficiently strong to justify a prudent person's belief that the person being arrested has committed or is committing a crime.
For example, an officer who has evidence that suspects have committed a crime, such as carrying an unlawful weapon during a robbery, has the necessary probable cause to make an arrest. Hence, the correct answer is that police need probable cause for an arrest, which is not explicitly listed as an option in the question provided.