By "race riots" do you mean the riot of 1967 or the grand daddy nationwide riot from MLK's assassination in 1968? In April of 1968 most major cities across the USA has widespread arson in addition to sniper attacks against police and government officials. It affected every major city across the nation. It's why the The Pentagon's Army Operations Center mobilized airborne infantry units across the nation to forcefully put them down because leadership thought a second American civil war might be kicking off. It's kinda ironic that the mass violence surpassed the government estimates of what the backlash would be in response to his assassination that the same week the White House and Congress rushed through American's first legislation to begin rolling back Jim Crow.