Clearly, there are situations all around the world every day in which people are murdered. If you focus on this one detail, then it's absolutely true that the murders in France are no different from any other murder, yet people are responding to the situation with a drastically different reaction, so clearly many people are seeing a difference that you might honestly not be seeing, otherwise nobody would be responding the way they are.

If this is truly the case and you truly want to understand what people are seeing in this specific situation that differs so greatly from other murders, then the solution is to take a step back and observe and compare the situations in their contexts, then attempt to determine what all is different about said contexts.

The difference is that emotionally, this feels so much closer. The middle east has been a center of conflict for decades now, large and small. People grow used to there being war there(and thus terrorist attacks0. Paris, however, is close to home for most of us, and many people have relatives there, or know people.