Whether Brown had a “juvenile arrest record involving second degree murder” is irrelevant IF he surrendered to the officer and was shot.
On the other hand, if Brown has a violent juvenile record, then there was rioting and looting over a run-of-the-mill thug getting shot by the police after a convenience store robbery. That’s one heck of a change from the initial stories we heard about a “gentle giant” who was innocently strolling home before a police officer shot him for no reason.