CHARLESTON, S.C. — Dylann Roof was convicted Thursday in the chilling attack on nine black church members who were shot to death last year during a Bible study, affirming the prosecution’s portrayal of a young white man who hoped the slayings would start a race war or bring back segregation.

Instead, the single biggest change to emerge from the June 17, 2015, slayings that shocked the nation was the removal of the Confederate flag from the South Carolina Statehouse, where it had flown for 50 years over the Capitol or on the grounds. Roof appeared with the flag in several photos in a racist manifesto.