I think as someone else said, he knew the police would be coming so if there was anything incriminating (I’d imagine he’s not that stupid to keep anything like that at his home) then it won’t have been there. The police know what he’s been up to, they just can’t do anything without enough evidence. Which ultimately lies with witnesses/victims who can’t or won’t come forward.I can believe him claiming he is innocent and they might have had or have suspicions but because the police never found anything, they see him as innocent.