Why would a burner phone possibly be involved if CT is the perp ?
Did MB have any life insurance ?
Not saying CT is the perp by any means but if she were, a burner phone could be used to send fake creepy messages or to lure MB to the church early (perhaps by pretending to be someone else). I don't even know who I think could be the killer so this is not to suggest I think CT is. I just am explaining why a burner might be used. All JMO