18 U.S. Code § 2331 as set forth in the USA PATRIOT Act, defines domestic terrorism as acts which
(A) involve acts dangerous to human life that are a violation of the criminal laws of the United States or of any State; (B) appear to be intended— (i) to intimidate or coerce a civilian population; (ii) to influence the policy of a government by intimidation or coercion; or (iii) to affect the conduct of a government by mass destruction, assassination, or kidnapping; and (C) occur primarily within the territorial jurisdiction of the United States."
According to this NBC News article, the U.S. Department of Justice officials have stated the following
In listing the reasons for seeking the death penalty, federal prosecutors said Roof "targeted men and women participating in a Bible study group" at the church "in order to magnify the societal impact" of his shootings.
His acts were also racially motivated, the prosecutor said. "Dylann Storm Roof has expressed hatred and contempt towards African Americans, as well as other groups, and his animosity toward African Americans played a role in the murders."
From everything I've seen and read of Roof, he was "radicalized" yet I haven't read anything about the church he attended, other congregants of said church or his family members being put under surveillance. Instead, I remember everyone feeling sorry for his family, at times it seemed more sorry for them, than for his actual victims and their families.
So I'm not misunderstood, I believe that when an acquaintance, loved one or family member does the unthinkable and commits a horrendous crime that results in the death of numerous people, that a certain amount of empathy and compassion is appropriate. What I'm attempting to point out however, is that when the perpetrator is a member of a certain religion, race, ethnic group, etc., then the act of that one person has always been presented as sufficient cause to condemn and violate the rights of a enormous swath of individuals who may or may not even know the perpetrator(s), let alone have had anything to do with their crimes.
If Roof was Muslim, no one in his environment would be left unscathed. The mosque that he attended would be cited as the cause of his alleged radicalization whether that's where he picked up his racist and murdering ideas or not and it would be put under surveillance. All of his family member would be subject to roving wiretaps, followed everywhere they go, their internet and electronic communications collected and sifted through as well as all of their financial transactions. That's just for starters.
If you're a white Christian and someone subjected you to all of this just because your crazy uncle or someone from your church shot up a Black church, in another state, would you not be outraged? Would you not feel that something had gone amiss if your government doesn't care whether or not you're a terrorist or had anything to do with crimes committed by others yet uses some tenuous connection such as you both being Christian in order to justify it's continued violation of your human, civil and Constitutional rights in direct contravention of it's own legal codes?
In the DOJ's own words, they acknowledge that Roof's actions were meant to "magnify the societal impact of his shootings". Doesn't this meet the second criteria for "domestic terrorism"? Why then isn't he and everyone else that has any connection to him, no matter how remote, not scrutinized in the same manner that Muslims are in the United States?
I believe the real answer is because most would find that extremely offensive.