What many people do not understand is that being questioned by the police is not the same as being under arrest. Until an officer has formally detained you in Michigan, you are free to walk away from him or her and the situation. However, an arrest occurs when an officer does not allow you to leave. Whether or not the arrest is legal largely depends on the existence of “probable cause.”
According to FindLaw, the Fourth Amendment of the U.S. Constitution grants citizens the right to be safe in their persons, papers, houses and effects. This amendment protects citizens against unreasonable search and seizures and unlawful warrants unless law enforcement has “probable cause,” and evidence to support such cause. The founding fathers thought up the idea of probable cause to avoid the formation of police states in which law enforcement can make unjustified arrests.
Since the creation of the constitution, courts have established that probable cause must be based on objective evidence and not just hunches or suspicions. “Evidence” may include several things, including observations known patterns of criminal activity that create misgiving; police expertise, such as detection of tools criminals commonly use, gang signs and threatening gestures; information gleaned from informants, witnesses or victims; and circumstantial evidence that indicates criminal activity.
Though officers must establish probable cause before making an arrest, a judge can later determine if probable cause did, in fact, exist. If a judge decides an officer did not have probable cause, any evidence he or she attained without probable cause becomes inadmissible.
You should not use this article as legal advice. It is for educational purposes only.