This episode was really hard to listen to due to the topic of sexual abuse , but I think David is on the right track and it's obvious who killed her.
Warning: my following post will be discussing sexual abuse and talking about what was said on the podcast.
First off, Jocelyn Martell who I believe was a friend? Said that the Sunday after Mel went missing, Dennis came over acting really weird. Jocelyn noticed marks on Dennis arm, but he told her that he recieved the scratch marks while Dennis was looking for Mel in the woods. This story conflicts with the story Dennis told Mels mother and his wife where he recieved the scratches play fighting with Mel. Jocelyn also said after she noticed the marks which looked fresh, Dennis started to tense up and stated he needed to go borrow Lionels dog to look for Mel. (This screams red flags to me)
Next, Dennis's best friend Lionel Martell (Jocelyns brother) confirmed the new story about the scratch marks and how Dennis got them looking for Mel. Lionel said that Dennis was a huge drug addict which had a huge impact on his personality. That Sunday after Mel went missing, Dennis did borrow Lionels dog from him, but told Lionel that he was going to use the dog to help the police search. There is no confirmation that this happened. This is the scary part, apparently Dennis had a huge problem trying to solicit underage girls, and the friend even called him out on his behaviour. Apparently there was an incident where Dennis drugged an under age girl, and as a result was charged and sent to jail. This poor child was not the first girl he had been charged with drugging and raping. Lionel also stated that Dennis use to get really high, and had mentioned to Lionel that Mel and another girl will "never be found, they will never find them". Lionel states, he can't remember the other girls name but that it was a unique name. He never questioned Dennis, and stopped seeing him soon after.
Next Stephanie (Dennis's daughter) talks about her dad. I sympathize with her so much as I had a father like hers, and I totally understand when she says she "grieves two people; the person she knows, and the hurt from the person she doesn't know. Steph was 6 when Mel went missing but she is a huge piece to this puzzle. Stephanie starts off by talking about how Mels family and their family were super close. All of the kids hung out and the parents had been friends for years. Stephanie talks about how her father had a lot of demons and she could literally see him "switch" when he got in a mood. It was found out after Dennis died that he was diagnosed with split personality and hid it from the family. Stephanie then talks about how her dad use to prey on her teenage friends, and that she even had to save a friend from her father at one of her parties. Dennis use to always offer rides, and Stephanie admits that's when he would try to assault these young girls. She states her father was actually charged with sexual assault when he attacked Stephanie's friend and he reoffened in 2014 before he died. Steph was also there before his stroke, and said she thinks it was brought on due to the police and Melissa's mom wanting to re-interview him. Apparently this actually made Dennis appear sick, and Stephanie said he looked spooked. It was then he told Stephanie that he didn't actually go on a fishing trip, he went to a motor rally and borrowed his sister's car; a light blue Toyota tercel. This seemed odd to Stephanie because Dennis owned a truck, so why would he borrow his sister's car to tow anything? Dennis was flustered when she left, and then had a stroke 4 hours later which left him immobile. She also talks about a "dream Dennis had" where he killed Mel, and Steph stated her father was distraught when he told her about this "dream". Later while in a health care facility, the police wanted to talk to Dennis again, and Dennis who was now limited in verbal communication was very VERY upset. He grabbed his daughters scarf with his good hand, and twisted the scarf as if he was going to choke her. He let go when she told him she would get the police out of his room. He died not long after.
I'm not going to say her name, but Mels sister describes helping Dennis where he tried to take advantage of her. He proceeded to take her to a Motel on the outskirts of New Liskard, and used drugs and got naked in front of her. Dennis tried to assault Mels sister, but she texted her boyfriend and told him if she didn't make it back to call the police. Apparently Dennis was describing what he thought she looks like naked, but I personally think he was trying to re-live that awful moment. At the end, David asks what her mom thought of that, and Mels sister states she has never told her this story...