H H Holmes was called a suspect in the Carrie Brown murder. So to have even a distant relative of George Damon playing him would be close to strange.
No, he wasn't considered a suspect in the Brown murder. Just because some deluded person suggested he was within the last few years doesn't mean that's so.
There isn't one reference to him being linked to the Brown murder other than the claim made by that individual who was involved in the dreadful American Ripper series.
Not certain either if Matt and George are related, are we ? You, yourself, said you went out on a limb in suggesting it a while back.