re: Sanhedrin 72a. CM 425:1 if we are clear that he does not intend to kill, we are not allowed to kill – as clearly seen in Gemora’s discussion about father/son
interestingly, Gemora is also discussing a difference between owner and a vigilante
Pesachim 2b is ganav and a similar discussion that if it is clear to you that he is not planning to kill, you also do not.