My understanding is that Gannon offered to take a DNA test; a link was posted up thread about it. It sounded like she didn't take him up on his offer but I'd have to go back through the entire thread to confirm that I read that correct; it was several days ago and perhaps I'm mistaken.
I read in an interview I followed links to that the mother did indeed try to obtain DNA from this man and he has evaded her. She was told by a number of molested children/now adults that he is her son. Time will tell. I think I would have had a private detective obtain DNA or fingerprints on the sly. Hard to do with the man's shaved head and all though.