How would someone know she was there alone? I thought in the beginning that the two brothers went to work construction out of town and the fiancé wouldn't have been with them on a job site. I finally realized she went with them.
We don’t know if they all rode together or had separate vehicles.
I think there is a garage at the house also - a vehicle could be in there and you wouldn’t know unless you were staked out at the road watching the house constantly.
It’s like so many other current unsolved cases....he/she was there and suddenly poof! they’re not with few clues to find them.
I've lived in the rural midwest for most of my life and believe me, in small towns everybody knows everybody else's business. I'll bet there were a lot of people in Brooklyn who knew she was staying there alone.