one more note on this tonight because there is more reporting on the man who allegedly drove his car into that crowd. authorities now releasing records of 911 calls, his past and his alleged treatment of his own mother. here's abc's senior justice correspondent, pierre thomas. >> reporter: tonight, disturbing new details about james alex fields jr., seen here shouting about white power -- >> white sharia now! >> reporter: moments before police say he rammed his car into that crowd. his mother says she knew he was going to a rally, but was unsure what it was about. >> i didn't know it was white supremacist. i thought it had something to do with trump. trump's not a supremacist. >> reporter: 911 transcripts released to abc news portray fields terrorizing his wheelchair-bound mother from 2010 to 2011 three times. in one call, samantha bloom told police that her 13-year-old son smacked her in the head and put his hands over her mouth.