Agent Murdered while showing up scale home

I was so saddened when i read that a young Real Estate agent was murdered when showing a vacant up-scale home in Canada!  A year ago, an agent was raped in our town, in a vacant home,but she survived it.  It just shows us that we need to be extremely cautious when showing vacant homes, especially since their are so many foreclosesures, many of the homes I show are vacant.  This doesn't mean that it happens only in "bad" neighborhoods.  I always let a close friend or my family know where I am going and what time my appointment is when showing vacant homes.  I have actually brought my husband with me before if I have never met the person before and are meeting them for the first time at the property, but is it enough?  It is very scary to think about how horrible an out come could be when we are just doing our job.