If I had to decide who was involved in John's death, I would choose Higgins 100% based on his pursuit of Karen Read, when he left the Alberts at the exact time John was arriving, and the delay of an hour for him to get to the CPD. For that matter, why did he return to the CPD in the first place in the middle of the night! Outrageous behavior after a day/night of drinking. For all we know, John and he had words outside after John left Karen's vehicle and before he entered the Albert home. Maybe Higgins had stepped out into the breezeway at the same time John was about to enter. We don't know. Maybe they stepped to the side of the house and got into a fight. We don't know. Maybe his body was kept in the back/side yard until Higgins figured out what to do during that missing hour. The fact that these clowns the Alberts had no security cameras is unbelievable to me. Karen had her head down at this point in her car, as all people these days do, looking at her phone, and the snow had started, so it's not like she was looking in that direction. I think BA got involved after the fact to protect his best buddy Higgins, hence all those butt calls at 2:30AM. There is more than one scenario that could have happened. There is plenty of reasonable doubt for a NG verdict IMO.
MOO