Of course. There's obviously a lot of speculation, particularly locally where many people have got (in my opinion) carried away with ideas of human trafficking and Polish cartels), but I'm really of the belief that it's played out in a relatively straightforward way.
My theory - he didn't set out to kill her, but he did. Perhaps by accident.
I believe he's offered her a lift back to Welly to retrieve keys or suggested waiting it out in the warmth of his car outside of her house. I can see why people have suggested he offer to break into the house for her, but I don't buy it. He's not a master cat burglar. If you've ever locked yourself out of a student house and had to call the letting agency out of hours or pay for replacement keys, you'll know it's not cheap. I can't see LS, drunk or otherwise, consenting to someone else breaking a window or door on her behalf.
He sets off from Haworth Street, ostensibly in the direction of LS's house. At this point the car leaves the main road and CCTV coverage. What happens next, I'm not sure. She's either blacked out from the alcohol or there's immediate intent on the part of PR and foul play - I'm leaning towards the former. I believe he's seen an opportunity in her incapacitation and parked up in this area close to the entrance of the park, and only slightly down the road from LS's house:
Google Maps
Somehow, he's coaxed her out of the car and into the park.
It
is a big jump from the crimes he's currently accused of to murder, so perhaps it hasn't gone quite like that. I think he's tried to sexually assault or rape her, and in trying to subdue her he's strangled or suffocated her, either killing or rendering her unconscious. He's out of his depth, he's panicked, and he's bundled her into the river - which wouldn't be an easy task as it's over a steep embankment. Then he's ran. I don't think he's spent any time with her body in his car, because it's just too risky.