Should we not have seen him putting some valuables on the hallway floor for collecting the stolen goods at the end from there?
I haven't been a burglar until now - how would a burglar have worked on his mission to steal? I assume: not in the way, this SP did. How did he escape so fast WITH stolen goods? If he didn't escape with stolen goods - why were there no goods placed for later transport, when SP left in hurry?
No disrespect intended -- you make reasonable points about what we
think burglars do - but we don't know what we don't know, so we don't know if this was a non-burglar who took nothing, or if it was a failed burglar whose attempt to rob went wrong.
One example of what we don't know, we have no way to know what sort of time schedule SP thought he was on. That would change everything. We can paint a reasonable scenario where SP wants to rob whatever's there, and decides he needs to be out the door by 6 or 6:30, before it gets light and LONG before anyone will be there to work. He is going to arrive at 3:30, scout around the place for an hour to see what he wants to take, then start collecting and loading from 5:00 to 6:00, leaving plenty of room to spare. He's unfortunately interrupted at 4:15, long before he has decided what to take, but he's not staying.
Problem is, criminals can do it however they want. There are no rules for intended burglars. Or for non-burglar trespassers. Or for intended vandals. Or for intended killers. We can't look at the way they acted in the heat of the moment and know what was in their mind when they walked in the door, unless they tell us. Intent could have changed at any time in the process.
Most importantly, we can ask the same sort of questions about why SP, if there to
kill, did this and that. Just like some of his actions would seem amiss for a burglar, others would seem amiss for someone who just came to shoot MB. He doesn't really fit there either. Only when he is caught will we find out if he was a burglar who killed, a killer who also looked for something to steal, or just someone on a lark who decided to play killer with a random person who walked through the door. The one thing we do know, it was clearly a loser, who gained nothing by being there, and who is still a loser.