General homicide rate among general U.S. population in 2010 (
http://www.cdc.gov/nchs/fastats/homicide.htm):
5.3 homicides/100,000 people/Year
3.6 gunfire deaths/100,000 people/Year
There were 794,300 LEOs in 2010 (
http://en.wikipedia.org/wiki/List_of_countries_by_number_of_police_officers ) so using 177 and 67:
22 deaths/100,000 LEOs/Year
8.4 gunfire deaths/100,000 LEOs/Year.
Assuming those numbers are reasonably correct, then LEO's are about 4 times more likely to be killed than the average person, and about twice as likely to die by gunfire as the average person.
I don't look at what put the person in harms way as determining whether I should feel for their death - it is by its very nature not something I apply rational thinking to. I don't think one is being cold or heartless for not feeling for someone else's death. There have been billions who have died and billions more to go; I don't have that much empathy to spare. I'm not sure I can grok all the mortality that existed and will exist in this universe.