After throwing a dinner party on New Year's Eve, Ana Walshe and her husband Brian hugged their friends at the entrance to their Massachusetts home and closed the door behind them.
Gem Mutlu said he had no idea this would be the last time he saw Ms Walshe.
Nothing appeared to be amiss during what he described as an "elaborate" dinner with the couple at their home in the wealthy seaside enclave of Cohasset.