In reference to the answer provided from the link below
My point of view:
The military is an organization of people willing to protect other people's life and properties. For one to be in military, he must be bold and courageous enough to face attack from the enemy at the expense of his own life.
The Military symbols include freedom, peace and Human rights.
A short sighted person viewed the military as an association or group of killers and murderers. He that lacks wisdom is shortsighted.
Now if a military man kill in order to protect lives, that cannot be taken as a crime, because that is self-defence and the bible even backed it up.
The bible doesn't against or prohibit anyone from being a military or soldier.
Luke 3:14 And the soldiers likewise demanded of him, saying, And what shall we do? And he said unto them, Do violence to no man, neither accuse any falsely; and be content with your wages.
A military should in every way avoid killing a criminal, he should be able to apprehend criminal such that he shot at some place which are safer.