I'll start it off myself. I think that the fisherman (his name leaves me) that liked Abby is killing every one.
*SPOILERS***
1st, he is a fisherman and thus comfy in the water so could have put Cousin Ben under the boat. Also, he has a cleaver which could have been used on Uncle Marty and te priest. And when the preist is found, his head is impaled on a deep sea fishing hook. His is never around when the murders occur, and he knows he area very well, sinse he has lived their his whole life. There are more examples, but I need to head out for now. Hope for some interesting reasonings on here!
If you do not know, this show is a murder mystery on CBS in America and internet. It is similar to And the there were None by Agatha Christie. If you have time to try a new show out and aren't squeemish, I would recomend it. For those who are watching this show, this is a discussions area about the show. Who your fav character is, who you think did it, etc.