No I dont think killing for any reason is ever justified be it as revenge against someone or just because you want to hurt another person. In the book Kill the Possum I think the author is demonstrating to the readers that everyone needs to be responsible for their actions and aware of the consequences of the effects of their actions on others. Also the lies people will say when they want to protect what is close to them. As Dylan became friends with this family, Tim and Kirsty, he became drawn into and witnessed all the bad situations the family was dealing with and felt he had to rescue them from this life. This led to Dylan premeditating murder with Tim which in the end backfired and left When we hear about these events in the news and as the trial unravels you hear of the tragic events which lead to the murder of all too often innocent victims and it most instances there is a family feud , abuse and violence involved. There are lots of arguments to say when killing is justified as in the case of a war.
In World War II the Nazis attempting to kill all the Jews in the world was definitely not justified, but on the other hand the Allies killing was justified because they were trying to keep the Germans from taking over the world and because of this we live in the world we live today. There are instances when some people do not have any other choice as in abortion. A young girl has got herself into trouble and become pregnant unfortunately she is only 15 years old and her parents make her have an abortion, she has no say in this matter the decision is made for her. Is this fair should her parents make the decision for her? In conclusion each of the above needs to be justified on their own merits. Killing someone as punishment for what they have done to you is not always right but, of these justified I guess each has to be assessed on its own merits but deep down I believe that life is very precious and should not be taken away from anyone not matter what they have or have not done.