I don’t think it can be anyone who is alive’s heart because when the queen pulled the huntsman’s heart from his chest and later when she went to her heart room to crush it, it was glowing and beating and i think Emma might notice that. I think that it means it has to be someone who is dead’s heart. I think the huntsman’s heart was crushed so i don’t think it can be his. And i think that Regina is trying to set up Mary.