Why this was called 'Motive', I have no idea. Motive was never explained. It was if everyone interviewed, idolized him (you never know anyone in the family's name) and only had good things to say about him. His lawyer dangles the 'why did he do it' carrot in front of the interviewers' faces the whole movie and never lets them have even a nibble. His psychiatrist also does the same. My guess is he was either gay or raping his sisters, the parents found out, so he murdered all four of them so the truth about him wouldn't get out. I wouldn't put it past the filmmakers that this is actually poorly done fiction.
Review of The Motive
