The mass murder of nine African Americans — killed in the Emanuel African Methodist Episcopal Church in Charleston, SC, by avowed white supremacist Dylann Storm Roof — is another atrocity in a centuries-long history of racist violence aimed at terrorizing black people, from their days in slavery to their efforts to organize politically and join labor unions, right up to the present day.

Roof’s murderous actions show the connection between the openly racist terror of the old Jim Crow and the bland, bureaucratic justifications for the mass incarceration of African-American men and racist police murders that author Michelle Alexander calls the “New Jim Crow.”

These days, racist violence in South Carolina is mostly meted out by law enforcement — like the April 4 shooting of an unarmed African-American man, Walter Scott, in North Charleston. If Roof’s racist comments and casual discussion of his plans to murder blacks didn’t seem to stand out, it’s because such sentiments aren’t so far removed from everyday discussion in a system where police have so dehumanized blacks that they can be routinely gunned down, armed or not — not just in the South, but across the US.