The Fine Line Between Probable and Possible

By Det. Ivan Kaminsky, Adjunct Faculty – Criminal Justice

CTU Criminal Justice Degree - Probable CauseMany in the general public are familiar with the terms “reasonable suspicion” and “probable cause” but few are able to distinguish between the two.  While the rules are very similar, applying one over another can make a difference in how successfully police officers get to the truth in their investigations.

Reasonable suspicion can be summarized as information, conduct or descriptions that make a reasonable officer suspect that a person may possibly be involved in criminal activity.  The key word here is possible. The officer need only suspect that an individual has a crime in mind before interceding.

Probable cause is often described as information, conduct or descriptions that make a reasonable officer believe that a person is committing, has committed, or will commit a crime.  The keyword here is probable. Probable cause is a situation where it is probable that they have or will commit a crime.

Let’s look at an example. A police officer is driving through a closed strip mall at 3 a.m. on a hot summer night sees a man dressed in a dark hoodie, holding a screwdriver.  The man looks at the approaching cop car and runs off.  Certainly there is no evidence that a crime has been committed which would serve as probable cause to arrest the man, but any reasonable person would suspect that the man was up to no good.  Reasonable suspicion, in this case, is grounds for the officer to stop the man and continue to search for additional evidence to support probable cause.

Some might argue that absent probable cause, the cop can’t stop this man.  But not only can he stop this man, I would argue the cop should – he is negligent in his job if he does not.   Reasonable suspicion exists even if it is uncertain that a crime is being committed. The suspicious nature of this situation leads us to believe that the man “may possibly be involved in criminal activity.”  To let the man run off while the cop investigates to see if a crime occurred would be a mistake.  In fact, the officer could use reasonable force tactics such as tackling to restrain the man for further investigation if necessary.

There’s a very fine line between the two definitions, but it legally the distinction is what matters most.  Knowing the difference between them, and what actions can be taken based upon reasonable suspicion, is the key to good, old-fashioned police work.  

It’s your turn to decide – A police officer is sitting on the highway when a car zooms past traveling significantly faster than other traffic on the road. In this case does reasonable suspicion or probable cause give the officer grounds to pull the car over?

Image credit – Fotolia/Paul Moore

CTU Faculty - Ivan KaminskyIvan Kaminsky is an adjunct instructor in the Criminal Justice program at Colorado Technical University. A detective with the Chandler, AZ police department, he holds a variety of professional memberships and certifications in investigative techniques and tactics. He holds his undergraduate degree from Arizona State University and his M.S. degree in educational leadership from Northern Arizona University.