You both are wrong.  Police need reasonable suspicion that a person is engaged in a crime or about to commit a crime.  If a person is hanging outside a store that has been robbed, the police can articulate the need to stop and determine his dealings.  It's called a Terry Stop and has been confirmed legal several times by the Supreme Court.  You need Probable Cause to arrest a person for a crime you suspect them of committing.  A warrant doesn't even come into effect until the person has not shown for court or has been found to be charged by a District Attorney.  The community is woefully inept on what actually the law is that they have built their opinions around innuendo and guessing.  I'm glad  someone finally wrote an article from another perspective, now they need to delve into why the black community is contacted by the police more than any other race and more inclined to be involved in a deadly encounter.