There aren’t many sounds in Southern California more frightening than a wildfire. And we’ve been hearing them way too often, in a fire season that doesn’t seem like a season at all any more, but a year-round event. There are so many that we have to give them names to distinguish them -- the Sand fire, the Chimney fire, the Fish fire. Humans start almost all of the wildfires in California – but only 5% of those are bona fide criminal arson. Ed Nordskog has studied thousands of incidents, all across the country. He’s a detective and arson investigator with the Los Angeles County sheriff’s office, the author of the book “The Arsonist Profiles,” and he’s been testifying recently in the case of Harry Burkhart, the German-born arsonist who was just convicted of setting dozens of fires around Los Angeles over a single holiday weekend.