I always thought that Becky didn't leave the house, or at least not of her own accord (given the amount of forensic activity at her home). There were others in the house at the time ("heard her music turned off and door slam"), but LE and family have never confirmed who they were. If what the step-mum says is true - and there's no reason atm not to believe her - she saw Becky that morning. My guess is that step-mum and Dad knew exactly who was in the house when the step-mum left - unless they were suspicious from the start, I don't understand why they wouldn't publicly acknowledge them. The original kidnapping charge made me think that Becky accepted the offer of a lift from her step-brother to her boyfriends house (given how close they were), something happened en route or at the boyfriend's house and his girlfriend covered for him by providing an alibi (given the lesser charge of perverting the course of justice, I don't think she was complicit in the murder). It's also possible that Becky never made it out of her own house alive (given lack of CCTV) and might explain the ongoing forensics at her home (body transported in boot of step-brother's car?). I think the other 5 have been arrested because they live or are close to those who live in the house where the body parts were found, so at least one of them is involved in at least the disposal of the body. But I find it very hard to believe that all 5 of them were complicit. All IMO, just trying to make sense of it all.