Right then! When a colonist goes berserk and kills one of your favourite colonists, you kill them back for it. Well, how about, instead of mindless executions left right and centre, how about you make them wish they were dead rather than actually killing them? Maybe bring in democratic roles, like president, advisor (2nd in command), judge (court) etc. Add a courtroom, for trials of murder, and throw them in prison if found guilty.
IMHO
It would seem too much of a hassle and just something that would disrupt colonist work. Most players are probably gonna ignore this or do a firing squad/rightclick -> arrest/manhunter bait.