in fact. if he's a jailkeeper, then he would WANT to roleblock nemesis from investigating or pulling a shot and so forth, at the cost of protecting him for the night... so might as well use the opportunity to shoot that protected person himself and cause confusion so that the nxt next night, nemesis would think trigger is confirmed and won't target him... leaving trigger to do what he wants.
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theoritically possible in mafia forums but you can't shoot yourself in these games that we play here unless blade pulled a stunt on us. at least i think it's ever been done here.
so my opinion? not feasible here as far as i know.