I don't know what I would do. I know in this case, I wouldn't be able to find him guilty. I would have killed that piece of shit. He got off lucky.
Ever see the movie
A Time To Kill.
Yup, I've seen it. I have to say I can't remember whether the rapist was going to get away with it.
I think what bothers me about the case in the OP is the cold-bloodedness of the revenge.
As strange as it may seem I have more sympathy for a hot blooded immediate kill reaction.
But this stepfather did not, I assume, say 'I am going to fucking kill you' when he got the call. He went down with bail money, had a place to take revenge in mind, had a tool. I assume he was fairly calm and controlled when he picked the guy up.
I have to say I am not sure I want this guy on my block. the guy who comes home, finds his stepson raping his 8 years and beats him to death or spur of the moment grabs something in the room and sodomizes the guy. That guy I am much more happy to have as a neighbor.
But this guy set himself up as judge and jury.
Also it opens a lot of doors if we say he did not commit a crime.
Honestly, I am not sure what I would do if I were the judge and let's say the guy got found guilty of aggravated assault or some other intermediate charge. I do feel incredibly sympathetic to his rage and even to his violence with the provisos mentioned above. On the other hand I am in a position of closing the door on anybody whose family member is the victim of violence playing Clint Eastwood.
I also wonder about this guy, the stepfather.
I would also have more sympathy for the stepfather if the stepson was aquitted say on a technicality.