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Reasonable Suspicion & Probable Cause


In order for the police to question someone, search or seize anything on their person or property, or make a lawful arrest, an officer must establish two things: reasonable suspicion and probable cause. While these two burdens of proof are often used interchangeably, there are two legal concepts enforcement officials must meet to avoid violating a person’s constitutional rights. 

Reasonable Suspicion 

A law enforcement official can detain someone or pull a person over on the road if there is “reasonable suspicion” that a crime has occurred, is about to happen, or happening at the moment. If an officer has a feeling or inkling of a crime, that does not count as reasonable suspicion. 

For example, an officer witnesses a motorist driving without his lights on at night or commit another type of traffic violation, he/she may reasonably believe that the driver is operating the vehicle while intoxicated. When the police pull over the driver, officials can conduct an investigation. 

Probable Cause 

If an officer establishes probable cause during an investigation, he/she can make an arrest. The primary difference between the two legal concepts is that the probable cause requires evidence of a crime, instead of reasonably believing a crime took place, has happened, or is happening. 

In the event of a suspected DUI, if an officer smells alcohol coming from the driver’s breath or vehicle, observes the driver’s slurred speech or delayed responses, or notices the driver has a hard time walking, staying upright, or performing field sobriety tests, then the officer has enough probable cause to make an arrest. Failure to obtain probable cause means the defendant has an opportunity to suppress any evidence gathered after the arrest and subsequently get the entire case dismissed with the help of an experienced criminal defense attorney. 

If you have been arrested in Chicago, contact the Law Office of Steven Fine today at (312) 436-0638 and schedule a free consultation. Get more than years of trial-tested experience on your side.