[A2J]

Unless the cop had probable cause to believe the guy had committed a felony,

Why a felony? He could have arrested the guy for a misdemeanor as well.

[connectthedots]

A cop cannot legally arrest someone for a misdemeanor unless he personally witnessed the crime. The reasoning is that misdemeanors are minor crimes and because the cop did not witness it, it does not warrant arresting the suspect. The cop should issue a citation to the individual to appear in court.

Now if at that point, the suspect refused to provide some sort of identification to the cop, it would not be improper for the cop to arrest him in order to assertain his identification.