"Mr. Freeman reported that even after firing two shots, he still considered the decedent to be a threat observing him to [be] armed with the knife...viewing the decedent's evil intent expressed in his facial expression, he felt compelled to fire the third shot to attempt to get past this violent man to render aid and prevent the man from getting back up to harm anyone," the Pontotoc County District Attorney's Office said in a statement, KFOR-TV reported.