Gerry Koob seemed incredibly sincere to me. I do believe that he loved Cathy and is still devastated over her death, even after all these years. His eyes looked so honest and had so much pain behind them. He and Cathy may have been having a sexual relationship, but he probably would have felt like he had to protect her memory/integrity by not revealing it. Either that or her letter was pure fantasy. She may have been acknowledging her love and lust for Koob, without ever having acted on it.
I also believe that it's entirely believable that she didn't tell Koob about the sexual allegations, because she didn't even tell her family about them when she went home for her last visit. Priests and nuns generally keep confidences in a different way than the rest of us do.
The story about the vagina was indeed bizarre, but I believe Koob. The police were either corrupt or they were using repulsive tactics to try to get him to confess. Either way, they wanted to intimidate him. Most likely, the police officer used something that resembled a vagina for his disgusting stunt. It's too crazy for Koob to make up.
As far as Koob's alibi. I think the other priest misspoke when he gave a comment to the newspaper about driving from the wrong place; or the newspaper printed it wrong. He and Koob were obviously together that night, because they had the ticket stubs, restaurant receipt, AND passed the lie detector test.
Honestly, when the episode started to focus on Koob as a suspect, I instantly thought, "Don't go there!" My gut told me that he was completely innocent. The only reason the newspaper man acted suspicious of him was because of something a police officer said to him. Obviously, LE immediately goes to the love interest as the first suspect, so they didn't want to let that go -- either because the police officer who wanted Koob charged was trying to deflect from the real culprit or because he wanted an easy answer.
Sent from my iPhone using Tapatalk