I think what the boy did was morally and legally wrong.
I wouldn’t give him a harsh sentance because the crime appeared to have been a crime of passion. I find criminals interesting, and although I am FAR from an expert, this boy sounds like a perfectly normal boy who had one bad incident. If I were the judge in the case, I would carefully weigh the boy’s past history, his schooling, his general attitude, etc, before pronouncing a judgement. If I found this incident to be a one-time freak accident and the boy expressed enough sympathy, I would give him a sentance, but a light one. I wouldn’t want his future ruined because of this incident.
Now, I have not read all the details on this case, and it would be impossible for me to. Therefore, all my judgements are based on what it publically available. If there were any evidence that the facts appear to be different than what they seem to be, then I would weigh more heavily against the boy.
As for the moral part - I can completely understand the boy’s response. However, we have laws, courts, legal systems, all that fun stuff for a reason. He did not have irrefutable evidence this man really was his mother’s rapist. Yes, the man admitted to raping her, but I have read far too many false confessions to take one as fact, especially one said by a known drug user. What if he killed an innocent man? I sincerely doubt that this was the case, but it could’ve happened.
Now, I hate to use the slippery slope argument in this case, but I do think it should be considered. Suppose the accused rapist had a relative and the relative killed the boy for the murder of his/her relative. If we did not know the facts of the first case and were just presented with “individual kills boy who murdered his relative” a good deal of people would consider that action justifiable. Of course, you could just argue that if you looked enough at the case, the first one would appear, but I have found that isn’t always so. A line should be drawn somewhere and I think it should be drawn straight away.
This is not to say that if one of my family members were murdered I would not want to kill the individual responsible. Right now, I regard doing so as lowering myself to the level of the criminal. Perhaps I would change my mind.