I disagree. Murder certainly has a definition. Sentencing another person to die in a premeditated fashion (from the comfort of a courtroom) who poses no threat to you is unjust. It is unjust because the people making the decision are separated from the basic facts of what happened by many layers (lawyers' financial motivations, time, memory, corruption, religious biases, etc) that play out in a courtroom drama. Far too often (and there is a ton of data on this) people are wrongly convicted and either serve sentences or are murdered by the state for crimes they are not guilty of committing.