Unlike “suspect” and “material witness,” “person of interest” has no legal definition, but generally refers to someone law enforcement authorities would like to speak with or investigate further in connection with a crime. It may be used, rather than calling the person a suspect, when they don’t want their prime suspect to know they’re watching him closely. Critics complain that the term has become a method for law enforcement officers to draw attention to individuals without formally accusing them.
There is concern among critics that innocent people will be tainted by being labelled a person of interest.
The use of the term increased in popularity in 1996, after investigators and reporters named Atlanta security guard Richard Jewell as potentially responsible for the Olympic Park bombing. He was later cleared and won at least hundreds of thousands of dollars in settlements due to his claim that his reputation was forever ruined.
In criminal law, a suspect is someone who is under suspicion, often formally announced as being under investigation by law enforcement officials. Probable cause for an arrest exists when the facts and circumstances within the arresting officer’s knowledge are sufficient to warrant a prudent person to believe that a suspect has committed, is committing, or is about to commit a crime.
Once a person is determined to be a prime suspect (the person believed most likely to have committed the crime), the police must be careful to give the “Miranda warnings,” or or else any statements or admissions by the suspect may be excluded from evidence in trial. Once a suspect under arrest tell a law enforcement officer that he wants an attorney, all interrogation must cease, subject to certain exceptions.