The police suspect everybody

 A crime has been committed. A person has been robbed, assaulted, or shot. The police report of the crime says that officers are seeking to arrest the suspect. And the journalistic stenographers who file crime stories, often taken nearly verbatim from the police report, dutifully report that the crime has been committed by a "suspect." 

Much as I have belabored the Associated Press Stylebook over the years, its entry on the use of "suspect" is a model of clarity: "The word refers to a person who police, prosecutors or other authorities believe or say committed a crime. Do not use it to mean a person of unknown identity who definitely committed a crime. In other words, don't substitute suspect for robber, killer, rapist, etc., in describing an event, even if authorities phrase it that way. Correct: Police said the robber stole 14 diamond rings; the thief ran away. Incorrect: Police said the suspect stole 14 diamond rings; the suspect ran away. Conversely, don't substitute robber, killer, rapist, etc., when suspect is indeed the correct word. Correct: Police arrested the suspect the next day. Incorrect: Police arrested the robber the next day."

(A side note: If you do use "robber/killer/rapist" instead of "suspect" for a person who has been arrested, you are convicting them in print before trial.) 

That is, a "suspect" is a person whose identity is known; otherwise we should be using the various categories of "perpetrator." 

But the police evidently have no truck with the Associated Press Stylebook. 

And, sadly, neither do most of the reporters whose work I've edited over the past forty-six years.