Yes. A friend of mine was in jail and one of the other inmates apparently had a history of smashing smoke detectors and hiding the pieces under his foreskin.
As crazy is Chris is, there are people way crazier than him.
Phone records will absolutely be admissible. Screenshotted sections of a conversation probably won't unless they 100% match up with what's on Chris phone and the records. Bella deleted a bunch of her messages and edited the call audio which already raises concerns about any evidence that could come from her of Fiona. For all we know the leaked content could just be part of some really elaborate roleplay considering Bella fetishizes incest. I do not think that's the case, but screenshotted texts of a small portion of a conversation can't disprove that. They need the entire thing, which will probably need to be obtained from Chris' phone or the phone company.