It was the girl's boyfriend who moved the body - that's why he went to prison.
What I couldn't understand was this: there was CCTV footage of the pregnant girl buying two tickets to Manchester. It turns out she was going to run away with her boyfriend from school. So why didn't they get on the train?
And then she was in a cellar - why was that? She was with the boyfriend when he killed her brother, so why wasn't he the one in the cellar?!
None of it made sense.
And why didn't Lisa just say to the cops that she knew where they could find that guy? She knew he was wanted by Manchester Police. What advantage was there in her roaming around his building, given she was suspended and he was really dangerous? When she saw his car there she could have reported him. And when he saw her down the alley he really wouldn't have let her go.