Ex:20:13: Thou shalt not kill.
Dt:5:17: Thou shalt not kill.
Dn 13:53 In judging unjust judgments, oppressing the innocent, and letting the guilty to go free, whereas the Lord saith: The innocent and the just thou shalt not kill.
Lk 18:20 Thou knowest the commandments: Thou shalt not kill: Thou shalt not commit adultery: Thou shalt not steal: Thou shalt not bear false witness: Honour thy father and mother.
Rom 13: 9 For Thou shalt not commit adultery: Thou shalt not kill: Thou shalt not steal, Thou shalt not bear false witness:
Js 2: 11 For he that said, Thou shalt not commit adultery, said also, Thou shalt not kill. Now if thou do not commit adultery, but shalt kill, thou art become a transgressor of the law.
The early Christians were consistent about "thou shall not kill." Modern ones are far more selective.