well, according to the fbi stats, one of the key indicators of a serial killer is homosexuality or issues related to it. one of their chief guys wrote a book about it a few years back, its probably now banned as being hate speech. there were some ten major indicators they look for and if i recall correctly, the misundstood one had to have at least six of these to be a serial killer.
Serial killers account for less than 2% of all murders.