The narcissism in these kinds of people always expresses itself the same way. They all lie alike. In fact, the lie at its core is always the same.
Someone or something caused them to react or behave a certain way. Then there's a gaping hole between the convoluted beginning of the story and the breezy ending, and the middle section is just all so confusing. In fact, it's not even part of the story.
The beginning always sets the victim up to become responsible for things going wrong. What happened next is narrated in a way that a toddler would tell a story. ('And then Mollie was in the trunk') There's a giant leap to the outcome, which just sort of happened but has no details. In this case, Mollie is dead but it's almost like she either ran ahead of him and made that happen on her own, or it's simply a mystery and only God knows. And there were also cornstalks.
It's going to be quite interesting to see what the evidence from his car, her body, her possessions, etc. reveal. I will not be surprised to hear that there is only a single thread of truth to the story he told because there's always a piece of truth in Narcissistic story-telling. And the rest is a lie.
So when he says he drove, and circled, then he got out, then he ran, then he walked, then he talked, then she grabbed her phone, then she said yada yada, then blackout, then he had an awakening at an intersection and a broken ear piece in his lap told him she was in the trunk - I think maybe he really means this: He swiftly and aggressively abducted her by ambush, he did the phone grabbing, and she was under his control in a matter of seconds, incapacitated in some way to make her transportable, and taken to a location where she was violently assaulted and then murdered. And it was after a lot of other moving parts that there was a body drag and dumping.
I do not believe his story of how he encountered her and made contact.