THat is not the issue.
It could be a part of the issue.
Just like the policeman's past could be an issue.
If the Police Officer was a former Klansman it would be an issue.
So Michael Brown's past could be an issue as well.
If Michael Brown was a gang member with a violent past it could certainly shed light on his actions.
The issue is that he was unarmed and shot dead in the street.
An unarmed thug can still be very dangerous in certain circumstances.
I would not want an "unarmed" thug bashing my head into concrete.
That could lead to my death or serious injury.
I would feel obligated to shoot an unarmed thug that attacked me in a very violent manner.
I know you use the term "unarmed" to garner sympathy,
but unarmed means nothing if they can literally beat you senseless or beat you to death.