Evidence I believe exists:
Gabby and Brian visit national parks and monuments, arriving in Moab on or before August 12. Both are in town most of the day, while Gabby works on her youtube channel.
August 12 - 2 witnesses call in what appears to be a DV incident, with two people scratching, pinching and hitting. At least one other witness tells police their story of what happened (a friend of one of the people who called) There appear to be more witnesses to this event in downtown Moab.
Early evening August 12. The 911 call results in 2-3 local police cars following GP/BL out of town toward the. entrance of Arches NP. The police put on blue lights near the turn-off to Arches, which is where GP/BL were going to spend the night (per what the ranger says later in the traffic stop)
Evening August 12. Gabby is told it "isn't far" to her campsite and that Brian will be hosted by a charity that aids DV victims. LE takes him to a hotel in Moab, about 13 miles from where Gabby is staying. The police advise them to spend the night apart. We have no evidence that they went against LE advice. Police ensure that both members of the couple have their phones and Gabby asks them to make sure BL has his charger, as she thinks his phone needs charging. Gabby appears to talk to someone on the phone.
August 13. Trip resumes. Gabby's SM shows they intended 3-4 nights in Arches.
August 17. BL flies to FL. Gabby goes to a hotel in central SLC, presumably with the van.
August 21. The coroner's window for Gabby's death has opened. (4 weeks out)
August 23. BL flies back to SLC.
August 24. Photo of Gabby in Ogden, UT. Posted to Instagram as usual.
August 25. Gabby texts her mom that she is in Grand Tetons NP.
August 27. Gabby and BL at Merry Piglets in Jackson, south of GTNP. BL goes in and out of the restaurant, speaking in a low voice to various employees. Gabby cries on the sidewalk, goes inside to apologize for him. Cause of BL's irritation is unknown.
August 27, 6:30 pm. Youtubers (Bethunes) capture their van at an unnumbered, illegal campsite near the main NF campground at Spread Creek. Rules had been made about where people could camp, due to overcrowding. (I believe that LE has been able to find more campers with dash cams and more information about their stay there.) Gabby was dead for 3-4 weeks per ME, when she was found on Sept 19. This is 23 days out from the Coroner's date for Gabby's death. Within the window.
August 29. Brian catches two rides, near Colter Bay/Dam area. He becomes somewhat agitated when he learns he's going back to Jackson and not toward Moran Junction, which is the way to Spread Creek. There is no evidence that the van had been moved during this period. Brian has a backpack, but not much stuff in it. (I believe by now LE has more pictures of the van, due to campground hosts having noticed and due to several people having dashcams, be surprised if not - van is very likely still in the same place and Brian goes back to it). Gabby is either hanging out by herself without being seen or is already dead. No. one in Spread Creek has said they saw Gabby out socializing. This is the 3 weeks out - ME's window for Gabby's death has closed.
At some point during this time, Brian uses Gabby's ATM or Credit Card or Apple WALLET to take more than $1000 from her account.
August 30. Gabby's mom gets a text she believes is not from Gabby. No voice contact. No pictures.
Sept 1. 10:36 am - The van, without Gabby in it, crosses the FL state border.