The brother says they didn’t know the father. They did know he was a criminal.
The youngest brother was born after dad was nabbed. But the older children were living in Tucson when dad became bank robber.
http://www.tucsonsentinel.com/local/report/100217_paddock_tucson/vegas-massacre-gunman-grew-up-tucson-father-was-fbi-most-wanted-list/