The police must abide by a set of policies and procedures at both the state and federal levels. The U.S. Constitution sets forth basic guidelines for police to follow to avoid infringing on your civil liberties. 

Law enforcement does have tools of investigation at their disposal, and one of the most widely used ones is the concept of reasonable suspicion. When the police pull you over for a traffic stop, they may use this as a way to delve further into crimes they suspect you guilty of committing. Take a look at what reasonable suspicion is and how the police use it to lead to an arrest. 

What is reasonable suspicion? 

When the police have an inkling you have broken the law, they may want to ask you questions. In essence, they need to detain you to do so. Reasonable suspicion gives police the right to lightly frisk you for weapons. They cannot use any other evidence obtained at this time against you. Also note, the police do not have to announce their suspicions or that they are detaining you. Instead, they may merely continue conversing with you, all the while paying extra attention to statements you make or behaviors you exhibit. 

What constitutes reasonable suspicion? 

An officer must have a reason to detain you. He or she cannot merely believe you did something wrong. For example, you must fit the description of someone the police are looking for, or you must demonstrate behavior that gives an officer cause to believe you have violated a law. When driving, an officer may think you are driving intoxicated. To pull you over, however, you must commit a traffic offense, such as swerving between lanes or going too fast. Once an officer sees this infraction, he or she may pull you over and start investigating your intoxication level further. 

It helps to understand the type of constraints police officers must operate within, especially if you must pull over and interact with them.