I agree this has to stop but I also have to wonder.........
I know how much you hate politics so I will do my best to keep them out of this conversation but I dabbling may be necessary.
Law enforcement in both of our countries are stretched to the limit, between funding, education and training it is a wonder law enforcement has time to do much of anything. In the states (it is of my opinion) that law officers are glorified meter-maids writing tickets for speeding and improper turns all in the name of the dollar, they are not protecting or serving. There is an element in my country that wants to outlaw guns and place our trust in the police officers to protect us from a criminal element, I ask how can they protect the guy down the street when an officer is writing me a speeding ticket?
In the sad case you bring up you mention "in front of his mother, and men, women and children" you do not mention their actions, I assume knowing the country you reside in, that they did not just stand by and allow this to happen, but all too often people do just that, they freeze out of fear, panic or just not knowing what else to do, but you can be rest assured if I saw a man with a knife threatening a child he would find my 240 lb (108.9 Kg) body flying at his to do a bit of physical harm myself. All too often we do stand by and do nothing then are the first to point fingers at the police for not doing their jobs. At least here in the States, the police are no longer there to "protect and Serve" they are fund raisers because our elected politicians do not properly fund them.