I would assume that this Emeryville man was likely in SF for the same conference as Bob. I've been to many conferences where people nearly come to blows over some disagreement over whatever the conference is about.
There must have been a video source OR witnesses to a prior argument or something.
One of my guesses about this crime was in the ball park - Emeryville is just minutes away from the murder scene, over the Bay Bridge. Easy access to getting into and out of SF quickly. My speculation is that the murderer thought they could get away with it, given the crime rate in SF. It was pretty audacious, actually, for a non-stranger murderer to do what it did just a few hundred meters from the big new shiny police station. I also wonder whether there was some drinking and possibly other substance use at the conference after-event that the victim attended, and whether that person was there.
All I can say is that if this guy did it, he certainly did it in a manner that enabled him to be quickly identified. I'm also on pins and needles because I know a quirky tech fellow from Emeryville and I sure hope it's not him.
And I'll also eat my metaphorical hat, again. The guy who beat the fire commissioner has been arrested as well. I figure that last year's battle against the DA has had some effect (LEO's from SF in online forums have said that they saw no point in arresting anyone while the other DA was refusing to prosecute anyone).
It's interesting that these two high profile crimes got solved quickly, from my point of view. Makes me go: hmmmm.
IMO.