At this point it seems obvious that all LEO present at the scene were not honest about what went down. No one knows why the father fled other than the killers and the father; if you were ambushed at night by dark figures who didn't identify themselves and who to appear to have weapons, you would fight or flee too. This is a case of Thugs with Badges whose extortion racket turned to murder - no one is safe from those who wear the badge.