As the news filtered out -- a series of suspicious fires at shops, parlours and clubs connected to biker gangs, along with a shooting outside a suspected Hells Angels clubhouse -- it seemed logical to conclude that London had unwittingly found itself in the middle of a biker war. That seemed upsetting, but understandable. After all, we've seen this kind of stuff before. It seemed familiar and, in some strangely perverse fashion, almost reassuring. But then London police Chief Brad Duncan revealed police believed the violence was the work of street gangs. Street gangs? Taking on the Hells Angels? That's crazy, right? Yes, it is. And that, as one expert warns, is precisely the problem. "It is audacious," says Irvin Waller. "But street gangs tend to be audacious." A founding executive director of the International Centre for the Prevention of Crime, current president of the U.S.-based International Organization for Victims' Assistance, longtime professor of criminology at the University of Ottawa and the author of several books -- including the influential Less Law, More Order: The Truth About Reducing Crime -- Waller has advised officials in more than 40 countries about how to prevent violence. And when told about our police chief's view that London is seeing a battle between gangs and bikers, Waller issues a dour warning. "None of this," he says, "is good news." Shootings and suspicious fires are, of course, never welcome. But Waller says the very make-up of a street gang -- young men typically, he says, between the ages of 15 and 25 -- is a recipe for recklessness. "These are basically young men who likely dropped out of school, or are not involved in jobs," says Waller. "If they've started to get involved in the drug trade, which would be consistent with what your police chief said, then they're probably carrying handguns for their own protection. And once you start carrying handguns for your own protection, you're living a risky life." Whereas members of the Hells Angels tend to be older, wiser and more dependent on a well-organized hierarchy with established procedures, Waller says street gangs are, by their very nature, more careless and impulsive. This local conflict has likely been triggered, he says, by a desire for a larger share of the lucrative drug market. "Your typical street gang does not have links to Colombia or Mexico, so they are basically retailers of drugs," says Waller. "The Hells Angels may also be retailers, but they've been involved in importing and distributing drugs... The Hells Angels are usually higher up the drug food chain." Waller, who has studied street gangs in Canada and Mexico, adds gang violence often escalates. "Youth gangs are not good news because they end up shooting each other, and other people get hurt," he says. "And there's no doubt there's a lot more violence associated with gang activity in Canada now than there was 15 years ago... Dramatically more." Waller says street gangs and handguns go hand-in-hand. "Now, roughly 20% of homicides are (committed) with a handgun," says Waller. "But if you go back 15 years, it was almost none that were (committed with) handgun." "What will the Hells Angels do?" asks Waller. "I don't know. But these are dangerous acts. And my concern is, where is this going to stop?"