He commands them to "kill" other people for right reasons...
Exodus 20:13 Thou shalt not kill.
Deutoronomy 5:17 Thou shalt not kill.
Matthew 5:21 Ye have heard that it was said by them of old time, Thou shalt not kill; and whosoever shall kill shall be in danger of the judgment:
Romans 13:9 For this, Thou shalt not commit adultery, Thou shalt not kill, Thou shalt not steal, Thou shalt not bear false witness, Thou shalt not covet; and if [there be] any other commandment, it is briefly comprehended in this saying, namely, Thou shalt love thy neighbour as thyself.
Luke 18:20 Thou knowest the commandments, Do not commit adultery, Do not kill, Do not steal, Do not bear false witness, Honour thy father and thy mother.
James 2:11 For he that said, Do not commit adultery, said also, Do not kill. Now if thou commit no adultery, yet if thou kill, thou art become a transgressor of the law.
Either it's not ok to kill, or it is ok to kill. When Jehovah gave us the commandments they didn't read "Thou shalt not...unless you have a really good reason or you just feel like it.".