Found out for leaving such small children home alone is bad enough but if you need to add in the fact that the apartments were unsecured its a double whammy. In reality we have no way of knowing who was checking, when and what routes were taken etc. But if JT did enter via the back it would explain why she observed Tannerman straight ahead and GM/JW but they didn't observe her.
I've only recently watched the GA vid and hadn't until then appreciated that entering round the front was much further than entering via the back.
You are making the classic mistake of confusing the front and the back (well at least I think so).
The side of the apartment with the front door is the front.
The side with the patio door is the back.
You say:
"But if JT did enter via the back it would explain why she observed Tannerman straight ahead and GM/JW but they didn't observe her."
well I'll change back to patio door:
"But if JT did enter via the "Patio Door" it would explain why she observed Tannerman straight ahead and GM/JW but they didn't observe her.
Can you explain that to us please?