J.D. Dunn (portrayed by Dean Chekvala) is Henry's brother. He's a dark and brooding loner with tattoos all over his body that speak more to his true nature than he ever lets on in conversation. Being the only brother of the groom should have made him a lock for "best man," but J.D.'s barely a guest at the wedding and wouldn't mind just missing it all together. His childish antics make Henry's life more difficult, and sometimes there's a malevolence in them that makes everyone wonder if J.D. has some secret endgame.
He develops a friendship with Madison, and the two pull minor pranks together (such as setting off firecrackers in public). After seemingly leering at Kelly in the bar (although he was simply looking at her tattoo) Shane attacks him. Following Kelly's death, Shane grows highly suspicious of him, and this culminates in Episode 3 when he kidnaps J.D. and comes close to hanging him, although he is stopped by Abby.
In Episode 6, following the horrific death of Thomas Wellington in front of everyone, J.D. becomes an immediate suspect when Henry recalls that he claimed he had "one last surprise" for the group. This is compounded by the fact that he was convieniently able to find the body of Marty Dunn with Abby. J.D. finally decides to run and hide out at Cole Harkin's cabin. In Episode 7, Henry decides to help Sherrif Charlie Mills capture him, and he is finally caught and arrested. As J.D. is restrained, he tells Henry that "You'll feel pretty stupid when I'm locked up and people keep getting killed." It is confirmed to the audience that he is not the killer when Malcolm is butchered near the incinerator, despite J.D. being in prison. J.D. then tells Sherrif Mills the location of Harkin's cabin in order to help prove his innocence.
In Episode 8, J.D. is put in the cell next to Shane's, and the latter begins to mock him. J.D. grabs his throat out of anger. Deputy Garrett walks into the room to tell them to knock it off, and is shot by the killer when the lights go out. J.D. takes the dead deputy's keys and frees himself from the cell, despite Shane's protests that he'll only make himself look more guilty.
With J.D. on the loose and still a prime suspect in the murders, the rest of the group becomes fearful and starts stockpiling defenses against him. At the end of the episode, Abby finally sees him briefly and goes after him.
DeathEditAbby discovers J.D. behind a crate, bleeding out from an abdominal wound. Abby asks him who did this to him, but he only says, "This is all about you," before dying of blood loss. Abby then turns around and sees Henry covered in blood, but thinks nothing of it.
- J.D.'s final words to Abby proved to be correct, as both of the killers (John Wakefield and Henry Dunn) had Abby as part of their motivations.
- It seems that J.D.'s refusal to tell Abby the name of the killer before he died saved her life, as Henry was standing right behind her.
- It is revealed that Henry's almost obsessive goal to prove J.D. as the killer was just to throw suspicion off of himself.
- In a deleted scene from Episode 2, he is shown to be playing croquet on the Candlewick Inn lawn in the rain with Henry coming over to discuss his fight with Shane and the upcoming week.