The argument that it was an accident is so ridiculous that anyone who believes it was accidental need only imagine that the murderer was anything other than a cop. EVEN WITH THE RACISM INVOLVED IN THIS CASE, I'm certain the jury would have found themselves compelled to convict Mehserle of murder if he had any other profession. In fact, had it been the trial of Johannes Mehserle, electrician, or Johannes Mehserle, IT Specialist, or Johannes Mehserle, car mechanic, rather than Johannes Mehserle, BART Cop, they might have gone even farther than Second Degree Murder. It wouldn't be too much of a leap to argue that the murder was premeditated and planned, since he essentially rendered Grant incapable of movement and then EXECUTED him by gunshot.
The skin color of the victim gave racists everywhere, including the jury, a reason to presume that the victim had it coming, but even if the victim had been white, the cop would still get off easy compared to anyone else who is caught on film EXECUTING a human being, just cause he's a cop. People would say "Well, I think he feels just awful about what he did. He's definitely guilty of involuntary manslaughter, but we can't convict him of murder. I mean, he's a cop, so I'm sure he didn't intend to do something so awful. Besides, if we convict this guy of murder, then the next time we need help from the police, they won't want to step in and save us because they might get in trouble if someone gets hurt. We have to give this guy a break. After all, police officers are the ones who put their lives on the line every day to keep communities safe." The irony of believing that this guy was out there trying to keep the community safe, even though he just brutally executed a citizen, will be lost on them.