Rarely post so don't flame. LOL
I am willing to bet the floor plan of this mobile home is:
-Enter front door directly into living room.
-Bar straight across from front door that separates living room/kitchen.
-Look right and there is the dining room and door entering master bedroom. Master is probably only bedroom large enough to hold two beds, etc., etc. Probably bath inside the bedroom.
-Look left and small hallway with small bath to right of hall, bedroom at end of hall, bedroom to left of hall.
-Enter laundry room by going around bar, walk through kitchen and it is at end of kitchen (kitchen long and narrow behind bar). "Back door" is actually at end of laundry room and opens on the side of the trailer -specically what you are seeing in the picture
A relative has same exterior trailer so I bet the interior is similiar. If that is the case and GF did not go into bedroom/bath, then she easily entered out of the master bedroom opening into the living room, light in kitchen is across from her and she could have seen back door from there.
That said, I have been sleeping at my relative's home as above (under the influence of nothing!), I would NOT have noted door opening, light in kitchen on and have had relative enter that bedroom, get clothes out of closet and take a shower and leave and I never woke up!
I have no explanation for the deadbolted door other than I do believe someone could have entered the front (if no deadbolt) with little effort and exited through the laundry door by opening the dead bolt from inside.
As far as the block, if they rarely entered/exited that door, any kid playing outside could have propped the door open with block or partial block. I have seen ours bring all kinds of stuff up on the steps/porch while playing outside. That door could have been propped open before that night and not noticed.
