The magazine is criminally responsible for endangering the lives of their employees by publishing the cartoon. .....
So instead of blaming those who actually conducted the murders, you blame the newspaper.
The terrorists should be found and given the max penalty the law allows in France, which I assume is life. The newspaper did, however, knowingly agitate Muslims. I am not saying they deserved what happened, but they are not innocent victims with the exception of the police officer so far as I know at this point. This was an assassination of someone who continued to aggravate and taunt people from the perceived safety of his desk. Real world trolling can have greater consequences than a message board infraction/ban.