The "inciting" incident:
7-1-80: Grateful Dead fans, however believable their addled faculties may be, usually cite the band's 1980 album "Go To Heaven" as the nadir of their recording career, though "Alabama Getaway" and "Don't Ease Me In" became later concert staples. That year's tour still managed to bring out the tie-dyed and squinty-eyed in big numbers for an appearance at the Sports Arena. Advance press reports made it clear that local police were "on guard" for the expected influx of illicit drugs and illegal activity in the parking lot and audience seats.
Even before the show started, several people were arrested for smoking pot. One bust was witnessed from alongside the stage by Dead members Bob Weir, Mickey Hart and band manager Danny Rifkin.
The trio tried to intervene, cajoling onlookers to join them in separating the young potsmoker from police offers trying to effect the arrest. Cops pulled out additional handcuffs and arrested Weir, Hart and Rifkin for "suspicion of inciting a riot."
The three defendants had to return to San Diego several weeks later to face charges. Their offense was reduced to a low grade misdemeanor, fines were paid and everyone walked out of the courtroom with a grudge against the SDPD that lingers to this day. "We couldn't believe what fascists they are down there," Weir told Golden Scarab, a Dead fanzine, in 1999. "We almost never went further south than Irvine after that. We didn't wanna set the kids up to be busted by a bunch of gorillas with no education, who hate rock and roll music."