Like all practicing Muslims, you have every reason to feel a sense of deep horror, grief and revulsion at this gruesome murder, especially by the hands of those who are supposed to care and comfort those under their care. Let me tell you upfront that every Muslim leader or imam that I know of has expressed horror and condemned such acts. I do not know of anyone who does not. So it has nothing to do with the teaching of Islam. Islam does not sanction killing of anyone except through the due course of law; for killing a single life is akin to killing all of humanity as the Qur'an declares. Therefore, no one is justified to blame it on Islam.
As rational human beings, we also need to ask another question: Why is it that every time when someone who happens to be a Muslim commits a crime, it is always blamed on Islam as if Islam was a religion that teaches violence? Do we do the same with any other religion? Do we blame the Christians for the war crimes of America in Iraq or anywhere else in the world? For millions have perished in Iraq alone in the aftermath of the two gulf wars. I hope you have heard about the so called incident of 'duck shooting' in the first gulf war. It was never reported in the media as a major news item. The fact was that one hundred thousand Iraqi soldiers who had surrendered, laid down their weapons, and were retreating, were all wiped out through what was referred to as 'carpet bombing'! However, no one ever blamed Christianity for it, although George Bush-- who called himself a Christian with a divine mission--said that he always spoke with God before making any decision. Likewise, no one blames Judaism for the crimes of the Jewish state against the Palestinians (think of Ghaza war and the entire population still under siege! Think of Rachel Corrie, the peace activist who was bulldozed to death by the Israeli army!). The same can be said of other religions as well. The point I am making is, why the double standard? Why do we stereotype Islam and Muslims?
May God inspire us all with a sense of justice and fairness in judging ourselves as well as others.