These police women were ambushed, there is no need for a "lets give bobbies guns" knee jerk reaction, as if it would have made any difference whatsoever.
Only a fool would actually believe that possessing a gun makes someone impervious to being ambushed.
Its incredible the number of US police killed each year, despite them being armed:
http://www.odmp.org/search/year
Remember that many of the police shot in the US will have been shot with their own firearm. From 2000 through to 2010, 511 US police officers were killed by gunfire in the line of duty.
http://www.washingtonpost.com/wp-dyn...l?hpid=topnews
The US is a different situation however, where everyone is armed the police needs to be. Not so in this country.
There are countless instances of accidental shootings by police in the US, everything from mistaken identity to dogs being shot by police.
http://usnews.nbcnews.com/_news/2012...g-address?lite
Its not exactly rocket science, when you arm the police and firearms are present at every call out, more people are going to die.