A person's criminal history is an excellent reason to deny someone entry to Canada. This is the CBSA doing their job. 

As a woman, I would also raise with the Globe and Mail the questionable practice of calling men who transition to being women "she". Bradley Manning may have changed his name and his appearance but he is still a man who, in his military career, punched a female soldier. If a man attacks a woman, he does not get to be called "she".