In 2010, Ottawa saw 27,446 property crimes, and 14 homicides[1]. In general, about half of murders are committed by a friend or family member[2]. So even if the other 7 murderers _all_ started out doing petty theft, there's still only 1 in 3,920 laptop thieves who's going to kill someone.
Now, as a high-falutin' tech blogger for whom laptops grow on trees, that still may be an unnacceptable risk/reward ratio for you. But if a laptop represented a more substantial investment, its value might begin to approach the value you personally would place on, say, 50 separate scuba dives. Which, at a death rate of 1 per 200,000 dives, is about where the risk evens out.
[1]http://www.ottawapolice.ca//Libraries/Publications/2009_-_20... [2]http://www.ncjrs.gov/ovc_archives/nvaa/ch16hom.htm