Exactly. Something happened at 7:45. Was that the first sighting of Rivera circling the area of Boundary and Middle Str. and waiting for Mollie to arrive? Did he grab her and throw her in the back seat after she was seen on CCTV? Did he drive her to 1900 395 Ave and assault her, ending at 8:28? Is this where he put her in the trunk?
Since something significant happened at 8:28PM, why didn't he leave her there? I would expect a first timer to want to distance himself from the body immediately, but Rivera didn't do that. He drove some distance and carefully hid the body.
I also notice several maps speculating on his route. I'm perplexed with the complexity of the proposed routes. Why wouldn't he take the most direct route to the cornfield where she was found, and then the most direct route home?
Pink line is abduction to cornfield, blue is cornfield home in this map.