GetawhaleMasterKuniI'm surprised this hasn't been mentioned in this thread yet, but apparently the guy fit the description of a strong-arm robbery that took place prior.
"Police Chief Thomas Jackson said the officer did not know the teen was a robbery suspect at the time of the shooting..."
Important to note, but that doesn't make that point any less relevant.
Brown was 6'3" and 250lbs. Had he committed a robbery and was subsequently confronted by an officer, he may well have been in a state of belligerence which led to the conflict, which would corroborate with at least one eyewitness' account of things.
Note that I'm only playing the same game of hypotheticals that everyone else (including the media) is at the moment. It's the media's job to provide you with the most sensationalist rendition of events, and that currently is the storyline of "innocent defenseless minority murdered in cold blood by racist cop". Sure, this could be entirely true, but they both don't know and don't care.