As the police released him and then arrested him, I think it means he didn’t admit anything. If he’d admitted whilst in custody they’d have charged him then.
If TB was at the police station today, I’m sure the media (and locals) would have reported it, so I don’t think she’s admitted it either.
Police say her remains not located so i don’t think they would know if she was in the duffel bag - if he said she was, he wouldn’t have been released.
Hence I don’t think the interference charge is about the duffel bag. If they find her she could well be in the bag.
I’m so very broken hearted for Pheobe, I don’t think she ever had a chance