Katelyn Markham's Fiance: John Carter

What we know from the statements of John Carter:

1.  Phone texts tie to him to the 'crime scene'; that is, the last place Katelyn was reportedly seen. (It has not been declared a crime scene to date)
2.  He knows or believes she is dead; past tense reference highlighted on Nancy Grace.  He did not answer as to why he spoke of her in that manner indicating that this question is highly sensitive to Carter.
3.  The language suggests tension; that is, likely an argument that took place before he left her apartment.
4.  He showed sensitive hesitation regarding the timing of the polygraph, while on Nancy Grace.
5.  His claims of burning and "getting rid of" documents, via fire, in the middle of the night, are concerning.