For me it is believable she was raped but not so obvious she was murdered
In my opinion it is very believable she ended in the river on her own(not jumped in the river like someone suggested before but simply fell into it)
She was very drunk and disoriented, she couldn't even find her own home on the street with lights so why you think it is impossible she walked in wrong direction on the dark field
It is possible that she passed out during rape and after he gone she woke up and walked in wrong direction still drunk and hypodermic
I don't belive he planned any murder his behaviour after was too chaotic ,is difficult to belive he was studied river tide time to disposed her body (for me it is just big imagination people from this forum)
It is simple bloke not sophisticated murder it was opportunity crime
And he probably would rape again if he would go away with this rape but I'm not sure if he murder her and I hope judges will have doubts too.
I must admit I struggle to see why anyone would have doubts. I'm not sure what you mean by an opportunity murder. If you commit an violent act knowing death is an outcome that is murder.
You don't have to have plans. But actually he did. He found a park with a tidal river which he checked out thoroughly in the preceding days and that evening. He could have raped and left her anywhere.
He didn't drive randomly past her on his way to Tesco's he drove past whilst prowling round a student area which he'd already got details of. A ready source of young women. He stalked her.
Any reasonable person would look at the evidence and think it beyond all reasonable doubt that she died at his hands.
He was a dangerous sexual predator that has been terrifying women for years and whose behaviour is escalating.
Gets details of student housing. Prowls that area. Stalks her. Takes her to the park he's studied which just so happens to have a convenient river close to the North Sea despite other sites being available.
Witnesses hear screams after CCTV shows him arriving. A Witness notes screams stop. That witness sees someone matching his description leaving minutes after those screams stop.
An expert in the field suggests that whilst he cannot completely rule out drowning it would NOT be his likely cause of death. That expert suggests as best he can that subtle asphyxiation is his most likely cause of death tho it cannot be proved conclusively
After the event PR returns to the dark lonely park at high tide. Why?
After that return he again prowls the student area and commits another less serious crime.
She on the other hand can barely walk in a straight line and has been raped which is a violent act. Gets up and instead of wandering flatish path towards housing chooses less favourable terrain to get thru reeds and into a muddy river? Avoiding in the process a large pond that doesn't go into the sea
Nor reasonable at all IMO.