Considering units of the Marines got deployed to Los Angeles in April 1992, I don't know how much worse it could get. Incidents of violence were reported in lots of other places in OTL, from a bunch of cop cars getting damaged in Wisconsin to a molotov cocktail tossed at a police station in Las Vegas and unruly protests in Atlanta and San Francisco. The American consulate in Toronto got a bunch of windows broken.
I would imagine that a bad police response could get the riots to spread across several other cities, but you need sparks to make people go out in the streets in these other places and unless they have grievances of their own, those riots will flare out fairly quickly.