A few posts back I see people were discussing the reasons that the screams went on for 15 minutes. It's horrific to think about but she may have been in and out of consciousness. There are attackers that do this purposefully, either by knocking the victim unconscious or strangling, even reviving them at times, vile I know.
With this in mind and if the screams are connected, I doubt anything this attacker did was accidental.[/QUOTE]
I agree. His sister told the media that Libby asked him to take her home, but that doesn’t make any sense as she lives just around the corner and may not even have had her keys. So we know he very likely lied about the reason Libby was in his car to his sister/wife, etc.
I think he drove by, saw a very drunk, possibly semi-conscious, girl on a bench, and an idea popped into his head. He parked around the corner and weighed the idea up in his mind for a while before deciding to go ahead with it. He then drove her to the park to carry out his plan, at which point LS woke up a bit and realised what was happening, and began screaming. At some point he may have put his hand over her mouth to stop the screams, and LS died. Then he either managed to take the body to the river very quickly or - more likely in my opinion - ran off initially but returned after a while when he realised that leaving Libby with his DNA on her would very likely incriminate him. He then put Libby in his car and drove somewhere else to hide her.