. >> when you heard about the shooting in south carolina were you surprised that dloorn listene dylannistened to that mus? >> no. it's the gateway drug into that movement. >> until he started listening to that white power stuff. before the killings, roof even wrote an online manifesto, saying he felt awakened by the music. that he once wrote about in his music. >> that our race was going to be killed off the face of the earth that there was a white genocide. >> roof is not the first mass shooter who may have been incited into violence. in august 2012 wade miecialg page walkemichael pagewalked inh temple and murdered. he was a musician playing in the band definite hate. aaron flannagan last stayed page's background. >> he just immersed himself in the scene completely. he played in all kinds of bands in north carolina in southern california. >> reporter: page's band definite hate, advocated shooting nonwhites, saying they were an infestation, bent on killing the white race. >> the smoousk like any kind of messaging, resultings in calls to action. you have some bands like the angry aryans