In general, a law enforcement officer must obtain an arrest warrant from a judge in order to make a legal arrest. However, there are exceptions to this rule. The two main exceptions to this rule are: (1) If the arresting officer has probable cause to believe that a crime has in fact been committed, and there is not enough time to obtain a warrant, then the officer may make a warrantless arrest. (2) An officer may also make a warrantless arrest of any person who commits a crime while in the officer’s presence.
An Arrest without Probable Cause
An arrest without probable cause is invalid. An invalid arrest does not excuse criminal conduct. However, evidence that has been obtained pursuant to the invalid arrest can be excluded from consideration by the jury during a trial. It can also be a source of leverage in plea negotiations with the prosecutor in your case.
Your belief that an arrest is invalid is not a basis for immediate protest. Your protest can lead to a physical injury or additional charges for obstructing justice or hindering an investigation. Assert your rights respectfully and make a mental note to discuss it with your lawyer. He is in a better position to use that information effectively.