When a gunman took aim at the prayer group inside the Emanuel AME Church in Charleston, South Carolina — a symbol of hard-won black freedom in the South — the all-black congregation wasn’t a random target.

Although the killing of six women and three men inside "Mother Emanuel" will be prosecuted as a hate crime, media and government officials seemed to go out of their way to avoid labeling this as "terrorism" — until Friday afternoon.

The Justice Department announced it was "looking at this crime from all angles, including as a hate crime and as an act of domestic terror."

There can be no doubt that the church shooting was an act designed to spread terror and fear among black people in Charleston. The suspect, Dylann Storm Roof, admitted as much, reportedly telling police that he wanted to start a "race war."

So let’s say this clearly and full-throatedly: The Charleston church shooting was an act of domestic terrorism — the kind of violence that black Americans know all too well.

In a chilling testimony, one of the survivors reportedly said that Roof had reloaded his .45 Glock five times, telling his frightened victims: "You're taking over our country, and you have to go."

"They want to label it as a hate crime, not a terrorist act, [but] it's a terrorist act," said Milton Robinson, who was on vacation in Charleston on Friday. "It happened in America, and they don't want to say we have a society like that. If it happened in another country, the first thing we'd say is, 'This was a terrorist act.'"

Flowers and notes of hope and support from the community line the sidewalk, Friday, June 19, 2015, in front of the Emanuel AME Church in Charleston, S.C. Image: Stephen B. Morton/Associated Press

Half a century ago, a church with a mostly black congregation was targeted in a bloody attack. Just before the morning service on Sept. 15, 1963, a bomb went off at the 16th Street Baptist Church in Birmingham, Alabama, killing four girls and injuring many others.

Like Wednesday's bloody rampage, it was a terrorist attack on a church, meant to frighten and silence black Americans. Instead, the bombing sparked nationwide protests, and the Civil Rights Act, banning discrimination based on "race, color, religion or national origin," was passed the following year.

Change that dramatic is elusive; so much violence against black Americans goes unremarked, misunderstood and excused.

That was clear on Thursday when, after the church attack in Charleston, some trotted out the usual careless language that shelters domestic terrorists from responsibility: Roof was a “lone wolf shooter” who was “mentally unstable.”

But the attack was much more troubling than what the “lone wolf” theory suggests. The warped white supremacist ideology espoused by Roof –- evident in the racist flags sewn onto his jacket -– is a system of belief that all too many Americans still subscribe to. The Confederate flag, a symbol of reverence for the slave-owning past that the Civil War ended, still flies on the ground of the South Carolina state house.

Let's start taking seriously how Dylann Roof was "radicalized," just as we do in homegrown Islamist attacks. Where did he learn his racism? — Scott Wilson (@PostScottWilson) June 18, 2015

The Southern Poverty Law Center, which tracks extremist organizations, identifies 19 hate groups operating today in South Carolina alone, including two Ku Klux Klan factions and several neo-Nazi and neo-Confederate groups.

In fact, the main terrorist threat in the U.S. comes from right-wing extremists, not violent Muslim radicals.

"Just ask the police,” as Charles Kurzman and David Schanzer wrote just this week, examining the growing right-wing terror threat.

“Despite public anxiety about extremists inspired by Al Qaeda and the Islamic State, the number of violent plots by such individuals has remained very low,” they wrote, pointing out that only 20 plots –- accounting for 50 fatalities –- have been carried out since 9/11.

Right-wing extremists killed more than five times as many people in roughly the same time period, they wrote, citing a study from the U.S. Military Academy’s Combating Terrorism Center.

Aurelia Washington cries as she talks about her grandmother Ethel Lance who died in Wednesday's shooting, as she leaves a sidewalk memorial in front of Emanuel AME Church, Thursday, June 18, 2015, in Charleston, S.C.

After the church shooting, police arrested Roof at a traffic stop in Shelby in North Carolina, seemingly without drama. Officers handed Roof a bulletproof vest, as if he were the target. Except for the vest, it looked a regular traffic stop arrest.

Charleston, S.C., shooting suspect Dylann Storm Roof is escorted from the Sheby Police Department in Shelby, N.C., Thursday, June 18, 2015. Image: Chuck Burton/Associated Press

No wonder Facebook and Twitter lit up with comparisons of that image –- the white suspect escorted peacefully along by white officers –- with other encounters between police and black citizens we’ve seen recently, like the video of a white officer named Michael Slager who shot a black man named Walter Scott in the back just this April.

Video from the shooting shows that Scott was fleeing as Slager fired his weapon.

As David Remnick noted in the New Yorker, the lynching and killing of black men in America was once a “means of enforcing white supremacy in the political and economic marketplaces; they served to terrorize black men."

Roof’s attack in Charleston was meant to do the same.

Colin Daileda in Charleston, S.C., contributed reporting.