I sortof have a theory. It's really very simple. Since the Tacoma Guy has an alibi, I'm assuming he either was not in town or did not meet up with MC. Maybe they were supposed to meet at Shari's or something and she never made it. At any rate, he has an alibi. My friend that had the dream told me she watched the video of Mackenzie leaving the Academy, and the overwhelming feeling she had was that Mackenzie was "on a mission", and it wasn't to go get a cup of coffee. I think she was planning on breaking up with JV. She went to Target.....walked in and saw him and turned around and walked out. Maybe she gave him a note or left a note in his car for him to meet her at the boat launch. He met her there after he got off of work at 4 and they went down by the river to talk. She broke up with him. He flew into a rage and hit her. She fought back. He won. He hid her body. He chucked her phone in the river. He went to the spec house to clean up. If they had spent a lot of time there together, then he knew how to get in. Maybe there was a tarp and supplies there or someone's truck has some supplies that he took or maybe he even borrowed a truck. Maybe he called a friend. He went back to the boat launch and took her car up to PC to ditch it. He walked or jogged or hiked back to the boat launch or he had a friend help him. He went back to the boat launch in the dark and took her to Crescent Bar. I think he would have needed help........someone he really trusted. Maybe he tried putting her out in the river and it didn't work. Perhaps he got the call from RC while he was there, and had to leave her there. He couldn't go back because, after her car was found, I'm sure he was watched. I know he drives a black car. Easy to sneak around in the dark.
I know everybody says he is devastated and he could never do such a thing..........but, how many times have you heard that about a suspect, and it turns out that they did do such a thing in a fit of rage! Of course he is devastated and visibly upset! If he did this thing.........he has plenty to be crying about. Speculation