I was assuming you had all read the manual at some point beings you've been troubleshooters for a while. If you want to have specifically not read it, then we'll go with that and Meri will have to edit her post, probably to killng you
But Meri, it all depends on the superior. If you are never questioned about it, then you don't have to provide any proof.
You are legally allowed to kill people as Troubleshooters, and legally allowed to kill Infrareds as Reds, but you must be able to back up why if asked by a superior or another troubleshooter. If you can't back it up, then you can be shot for treason. If you are never asked, then you lucked out.