"You need to bring a gun that has a silencer on it and that can be easily concealed in your pants pocket or coat. ... If you do not want to risk the possibility of getting caught with a gun before the job, bring a sharp knife that is (at least) 4 inches long, it should be sharp enough to stab someone and/or slit their throat to kill them. I want the person to be dead in less than 2 minutes," says an email reprinted in the affidavit.