https://www.nytimes.com/2015/06/25/us/tally-of-attacks-in-us-challenges-perceptions-of-top-terror-threat.html?ref=oembed&_r=0

"Since Sept. 11, 2001, nearly twice as many people have been killed by white supremacists, antigovernment fanatics and other non-Muslim extremists than by radical Muslims: 48 have been killed by extremists who are not Muslim, including the recent mass killing in Charleston, S.C., compared with 26 by self-proclaimed jihadists, according to a count by New America, a Washington research center."