Unless the GJ requests it. BTW it is not permissible to withhold exculpatory evidence before a grand jury depending on whether it is a Federal charge (where you would be correct) but in some states it's required. AFAIK it's not the case in MO, but if evidence is asked for then it's considered prosecutorial misconduct to deny it. That's because the usual reason for suppressing it is to ensure the prosecutor can't overly influence for indictment, which happens all too often.
I think there's an argument to be made for requiring all exculpatory evidence to be presented, in every case. The prosecutor is supposedly neutral, but everyone has his or her biases. However, when it happens as an isolated incident - and the exculpatory evidence is exonerating a cop - it stands out. I can see arguments either way, but I'm not real comfortable with it as an isolated incident even though I understand the reasoning behind it.
Not off of weed alone which is what I saw as only reported so far. The right narcotics can cause someone to do this sort of stuff, but they wouldn't be acting as coherently as Brown is in that video. Strong enough drugs to affect the mind to do that affect the body's movements and other actions as well.
The video points to actions take by Brown as actions he has built up to over time and gotten away with in the past.
Maybe, although I knew a guy in high school who was so smoked up (weed only) that he rear-ended a bright red and white Coca-Cola tractor trailer in the middle of sunny day on a straight four-lane highway. He hit it three times; the only reason he didn't hit it four times was that the impact had driven the radiator back around the fan to the point of stalling the engine. When the truck driver reached him, Bobby was still steering even though his car wasn't actually moving, and he was lucid enough to hold a conversation with the driver but not lucid enough to stop steering. Doesn't seem like too much of a reach to extrapolate that to simply taking cigars and pushing whomever gets in your way. Granted, that requires a certain amount of innate violence, but that's in practically every teenage male. The ME was saying Brown was high enough to experience hallucinations; that would certainly impair one's judgement. Although full disclosure, I've been friends with a lot of people who smoked a LOT of pot back in the day and I've never heard of anyone having hallucinations from it unless it's tainted with something that presumably would have turned up in his blood. (I don't think it's a stretch to assume that the authorities left no stone unturned looking for something that made Brown look more culpable to save one of their own - not to mention maybe keep some of their city standing.)
Looking at it from the other angle, Brown was a very large black teenaged male, apparently without much money or connections. There simply is no demographic that gets less of a pass from our legal system than this one. If Brown had a habit and pattern of this behavior, I'd think we'd have seen evidence of it. Freakin' security cameras everywhere now. Even his social media accounts are clean - he didn't seem to smile more than once in a blue moon, but he wasn't acting all gangsta, which puts him ahead of most teenage males.
Grand Jury participants are not allowed to even out themselves as such, nor is the judicial system. Their anonymity is all but guaranteed. Even if someone in the press figures it out and outs one, those responsible, including the journalist is going to jail.
Yeah, but what's the odds that every single person knowing their identities is going to respect that anonymity? Republicans have repeatedly had legally-required confidentiality violated by government workers, and this issue is a LOT more heated than politics.