I'm not sure what the Ferguson Police Department's policy is regarding waiting for back-up, but it seems to me that much of where we stand today with regard to Michael brown's untimely death could have been avoided if Darren Wilson had just waited for help to arrive.
At the time Wilson first encountered Brown and his companion, Dorian Johnson the only crimes Wilson would have been able to observe were jaywalking and possibly obstruction of traffic--neither of which warrants the use of extreme force.
The ostensible purpose for the stop that Wilson cites was to get the two men out of the middle of residential road of which the two suspects were walking down the middle. When the two men refused, and began shouting expletives at him, Wilson, who was alone in his vehicle, should have fallen back, followed the suspects from the safety of his vehicle, observed and reported, and waited for more officers to arrive. It is likely that help would have arrived in minutes, and if it didn't, so what? The crime at hand was minor and not worth escalating.
The probable outcome when back-up arrived would have been that Brown and his companion would have backed down due to a show of superior force and numbers. If back-up took too long, Brown would have exited the center of the roadway and headed for his destination. He had just committed a petty theft ($38 worth of cigarillos) at a local convenience store, and he would have known it was only a matter of time before Wilson put two and two together from the radio calls, and brought considerable weight down upon him. Brown wasn't planning on loitering for too much longer; any hazard he was causing on the roadway was about to be cleared.
Wilson did, in fact, connect Brown to the robbery, and set about delaying Brown and Johnson until back-up showed up on the scene. This is the key moment in the interaction, and the moment that makes so little sense that it's hard to fathom. Wilson was alone; it was two against one, and at least one the suspects (an exceedingly large one) had already plainly displayed an overt and aggressive disregard for Wilson's authority. By blocking the men with his cruiser in the middle of traffic and getting out to confront the suspects, Wilson was virtually guaranteeing that there was going to be a confrontation wherein his only advantage was the firearm at his side.
Now, I'm not suggesting that Wilson should have resorted to cowardice, but instead that the John Wayne, cowboy shit that so many of our country's police forces still seem to encourage needs to go the way of...well, the way of the Old West. Caution would have served Wilson better than bravado that day. He should have been weighing risk versus reward. The worst case scenario if back-up didn't arrive in time and the suspects got away would have been that two unarmed black men, guilty of jay-walking and obstructing traffic, might have made off with a whopping $38 worth of stolen cigars. That would have been significantly less expensive than the way things turned out.