I'm not even remotely a competent artist so ignore the pathetic nature of June's body you are lucky it is not a stick figure.
The killer was standing around the K. The lines mark the trajectory of the bullets and show where the rifle was generally pointed for each shot. The reason the neck wound is in purple is because if red you would not see it because of the overlap over the other lines.
The yellow lines show where the casings would go from shots fired in such locations. You can see that the casings line up with where they were found.
The 2 chest wounds are the ones delivered when June was getting out of bed or entirely out of bed. Because she was getting out of bed her body was much further towards the door than when she was lying in bed. The killer had to turn to the right to aim at her and in turn this caused the shell casings to fall further to the right instead of with the others in the corner next to the bed.
As she was getting out of bed her right side was facing the killer hence the chest wounds also came to her right side. This is why all these entrance wounds are to her right side.
As I stated on blue many times, I personally believe that after emptying the gun and seeing that Nevill was coming after him that he fled to get more bullets. At that point June either walked around the bed to try to aid Nevill and walked back with him to the door but collapsed or after Nevill left to pursue Jeremy she walked around the bed for some unknown reason perhaps because she was in a daze then turned around and collapsed on her way to the door. Nevill in the meantime either walked towards Sheila's door and tried to speak to her but was unable to speak and thereby dripped blood on the carpet or he simply went down stairs as fast as he could and caught up with Jeremy in the kitchen as he was trying to load the magazine and tried to grab the weapon then Jeremy grabbed it back and they struggled and upon taking full sole control Jeremy then beat him with it until he was unconscious then reloaded in peace and shot him killing him. Then upon going upstairs he shot the boys then went back to the other wing and if Nevill didn't drip the blood near her door before going downstairs then it dripped off the weapon or Jeremy's gloves on his way to get Sheila. Either before he got Sheila or after he killed Sheila he fired a shot between June's eyes to make sure she was dead.
Nevill could not move that fast he was even bouncing against the walls as he was moving. Even if he managed to bolt past Jeremy somehow as they fought in the bedroom, Jeremy should have been able to catch Nevill before he reached the kitchen. So it seems more likely to me that Nevill chased Jeremy to stop him from reloading and to try to subdue him. I have been stabbed before. I was furious and went into a rage with adrenaline pumping. Between seeing his wife shot and being shot himself I am sure Nevill wanted to rip his head off. Jeremy was very lucky that Nevill's arm was broken or the outcome might have been very different.