i have to say that i still won't be surprised to hear that someone else may have been there. because the evidence does really point to a lot of planning and basically luck (or bad luck) for an 8 year old to pull this off by himself. part of me still wants to believe that somehow it wasnt him i guess, or that someone was directing him.
the following is my total speculation of what happened based on the facts i know.
SPECULATION NOT FACT.
the father and tim arrive home together in the same truck.
the boy is home already and is upstairs with the gun, the box of bullets is open downstairs near the couch so he probably waits downstairs watching for the truck coming then runs upstairs with extra bullets in his pocket.
tim stays in the truck to call his wife and the father goes in the house and heads upstairs.
there is a landing then the second half of the flight of stairs goes back the other way (180 degree turn) and as the father reaches the top of the stairs he is shot.
there is no blood trail near this body so its possible the father is shot in the head on the first shot, but my guess is he is shot in the chest, he is then shot 4 more times, several shots are to the chest and one of the shots to the head does significant immediately noticable damage.
the boy must know they dont enter the house together because he knows he has to reload and that wouldnt be likely possible if he is confronted by two adults at the same time. and as we know now it was tim's routine to call his wife after work, probably most often from the truck in the driveway after the father goes in.
remember that with the rifle he used, he is standing in the hall upstairs with it loaded and aimed at the stairwell, he shoots, then he must rotate the bolt handle on the side of rifle up and then pull it back about 4-5 inches(?). he probably has the stock of the gun tucked under his arm as he does this, and his other hand holding the grip on the barrel of the gun. then he has to grab another bullet out of his pocket, slide it into the chamber, and then slide the bolt forward and down into a catch position, then (unless he fires from the hip so to speak) he has to return the butt of the gun to his shoulder, aim and fire. he must do all that between each shot.
well trained adults can do it fairly quickly for sure, 8 year olds? i dont know. he can certainly do it, but under pressure? very quickly? i just dont know, but it sure looks like he managed it. 5 times.
then he goes downstairs and calls out to tim "tim, come in, something is wrong with dad, tim come quick", tim's wife overhears the boys voice on the phone and tim says to her "the boy is calling me, something is wrong, i dont know whats going on, i have to go" and he hangs up abruptly.
tim is about 8 yards from the door and the boy opens the screen door and shoots him hitting him in the chest, tim advances and is shot again in the chest, he still advances and is shot from below up thru his jaw, and then he is possibly on his knees or hands and knees and the boy has turned now and is facing the screen door and attempts to shoot tim in the head but misses and it enters the screen door from the outside travelling towards the inside of the house at a downward angle. he then does shoot tim once more in the head thru his hard hat which somehow amazingly still on his head (he also still had his work protective glasses on. again remember as tim is advancing towards the boy thru multiple shots, the boy must perform the procedure above after every shot.
the phone call is reported to have taken place just before 5 o'clock, a neighbors thinks he heard shots at just about 5 o'clock, and the 911 call is at approximately 5:06.
so the boy doesnt stay at the house long, maybe just long enough to put the gun down on the dog cage inside the door, and then he walks/runs to his friends house who calls his father at work, and the father calls 911.
MY SPECULATION BASED ON FACTS I KNOW.
ack i gotta go eat dinner, i will type some theories i have been considering when i get back.