Five Suspects are cleared. Ten remain. What case could be made against them?
Jimmy Tinker
By his own admission, he was at the Flint crime scene. He, of all the suspects, had the best prospects of making the killer film and developing it, as he was a film student. He had a motive for doing in Nate Flint. He might have come across the Burnt Man tape in a film vault at film school. G.D. accused Prudence Conner of shielding Jimmy Tinker. However, the case isn't very good beyond that point. It was unlikely he would have murdered Carmen or Abby, and he had no known motive for killing Leita Rose-Blodgett. His story about Abby's car strikes me as the truth. He smashed it up in a drunk rage, found the scene, and then fled out of fear. He's a weak suspect.
Mary-Elizabeth Merchant
She's a nut case, but she has no motive for any of the killings. Her involvement in the case is peripheral. She dumped the car in the drink for $600. She's trying to take over Abby's position at the church and with Jimmy Tinker. I doubt she would have the physical ability to dig up Oscar's grave. Weak suspect.
Prudence Conner
I had almost dismissed her entirely as being involved until the last episode. She had a bang stick. She's refusing to cooperate with the team, ignoring G.D. and his pleas to come forward. However, instead of being a killer, I think she's more likely to be a victim. Concealing evidence is a bad idea. She has no known motives for any of the killings. She could be in the clear if the team had gotten confirmation on her whereabouts for the time of the Flint killings. Weak suspect.
Emerson Bowden
The one piece of evidence against him is that he understands taxidermy, and the fingers in the sardine can led the team to him. Other than that, nothing. No known motive. Little air time. Likely to be the next elimination for the red envelope game. Very weak suspect.
Reverend Rusty Crandall
Rusty has no alibi for the time that Leita Rose-Blodgett was murdered. He was also late in turning in the tape. It could be that he had to edit it before turning it in. It's a point against him, but that's about it. No known motives for any of the killings. Weak suspect.
G.D. Thibodeaux
Early in the investigation the focus was on him. He was supposedly fired by Nate Flint, and he's irrational. He found the body of Carmen Flint. He needs help for his mental problems. However, he's provided an alibi for the Flint killings, though it has never been verified. If he was the killer, he would be unlikely to admit he owes Nate money for staking him the ferry business. Everything he's done shows that if he's treated like a friendly witness instead of a suspect, he's willing to help the team in his own rough manner. His mindset is too uncontrolled for him to be an organized killer. Finally, he was unconscious with Kristen when Brian was killed. Weak suspect; in fact, not a suspect at all unless he’s working with somebody else.
Samantha Larabee
As with Emerson Bowden, we've seen little of her. However, I can come up with a rather strange motive for her for the Flint killings. With the entire family out of the way, the money goes to C.R. Flint. It's possible, being so devoted to him, that he would leave his property to her, as his heirs are gone. It provides an unusual motive for the Flints, but nothing for the Leita murder. She lost her alibi for the Leita killing as well when the time stamp on the machine was proved wrong; just as she alibied Frank, he alibied her. Her pregnancy has nothing to with the case, except perhaps to increase the stress on Frank. Weak suspect.
General Hayden Debeck
The General was accused by Leita of having dug up the grave. Nice, but an accusation is not proof. Yes, it is possible his real target was Leita for dumping him all those years ago, and the Flint killings were a diversion to conceal the real crime. What better way to disguise a single murder than by making it a part of a serial killing? He controls the mysterious sweepers. He knows the town history. However, his love of the town would probably cause him to not want any murders. As it stands, his dreams are falling apart due to the actions of the killer. I don't consider him a strong suspect, but he's a little better than the weak suspects.
William Lambert
He's the person who's gained the most from the killings. He has a clear motive for killing Leita Rose-Blodgett, and also has benefited from the Flint killings, which put Nate's holdings into C.R. Flint's hands. As C.R.’s is declining, Nate has taken full control, and can build his hotel. A piece of his jacket was found in Leita's house, but as I've said before, he had every reason to be in the house. He owns a bang stick. Lambert has motive and opportunity. He's a strong suspect. However, I don't thinks he's as strong a suspect as...
Frank Kovick
Frank cannot alibi either murder; indeed, Frank's time period for the Leita murder would have alibied him until they found out the time on Reverend Crandall's answering machine was incorrect. He's a man under stress, and, of all the suspects, has the best resources to dig into the town's past, and probably is in the best position to have discovered the burnt man tape. He knows about crime scenes from his experience in New York. He has a boat, and is likely to know about bang sticks. He has a boathouse, a possible hiding spot for the 4 missing bodies (Nate, Abby, Leita, and Oscar). He has inserted himself into the investigation, something many serial killers do (though as a reporter this behavior is not unexpected). His puzzle was at the Leita crime scene. He's provided (indirectly) a motive of gain, nearly a quarter of a million dollars. He said he's been digging and came up with that. But we know by his own admission about the libel lawsuits that he'd been digging up dirt on Nate beforehand. He could easily have been monitoring those transactions, and known about the withdrawal. If he knew about the money and the withdrawal, he might have performed the killings for the cash as well as to stop the lawsuits. So we have motive and opportunity for him for the Flint killings. Leita blabbed to his wife about his affair. He admits going there, but says she was calm about it. Given his temper, he could just as easily have gone to the house with a bang stick. Right now, Frank is my prime suspect.