The problem is people not understanding the difference between the two words. Murder is illegal killing. If the intended meaning of “Thou shalt not kill” was just that—no killing—it would render all of the God-endorsed bloodletting done by the nation of Israel a violation of God’s own commandment (Deuteronomy 20). But God does not break His own commandments, so, clearly, the verse does not call for a complete moratorium on the taking of another human life.
https://www.gotquestions.org/you-shall-not-murder.html
Look at the difference in the 10 commandments in the KJV and NIV.
10 commandments KJV and NIV
Exodus 20 King James Version (KJV)
1 And God spake all these words, saying,
2 I am the Lord thy God, which have brought thee out of the land of Egypt, out of the house of bondage.
3 Thou shalt have no other gods before me.
4 Thou shalt not make unto thee any graven image, or any likeness of any thing that is in heaven above, or that is in the earth beneath, or that is in the water under the earth.
5 Thou shalt not bow down thyself to them, nor serve them: for I the Lord thy God am a jealous God, visiting the iniquity of the fathers upon the children unto the third and fourth generation of them that hate me;
6 And shewing mercy unto thousands of them that love me, and keep my commandments.
7 Thou shalt not take the name of the Lord thy God in vain; for the Lord will not hold him guiltless that taketh his name in vain.
8 Remember the sabbath day, to keep it holy.
9 Six days shalt thou labour, and do all thy work:
10 But the seventh day is the sabbath of the Lord thy God: in it thou shalt not do any work, thou, nor thy son, nor thy daughter, thy manservant, nor thy maidservant, nor thy cattle, nor thy stranger that is within thy gates:
11 For in six days the Lord made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the Lord blessed the sabbath day, and hallowed it.
12 Honour thy father and thy mother: that thy days may be long upon the land which the Lord thy God giveth thee.
13 Thou shalt not kill.
14 Thou shalt not commit adultery.
15 Thou shalt not steal.
16 Thou shalt not bear false witness against thy neighbour.
17 Thou shalt not covet thy neighbour's house, thou shalt not covet thy neighbour's wife, nor his manservant, nor his maidservant, nor his ox, nor his ass, nor any thing that is thy neighbour's.
Exodus 20 New International Version (NIV)
The Ten Commandments
1 And God spoke all these words:
2 “I am the Lord your God, who brought you out of Egypt, out of the land of slavery.
3 “You shall have no other gods before[a] me.
4 “You shall not make for yourself an image in the form of anything in heaven above or on the earth beneath or in the waters below.
5 You shall not bow down to them or worship them; for I, the Lord your God, am a jealous God, punishing the children for the sin of the parents to the third and fourth generation of those who hate me,
6 but showing love to a thousand generations of those who love me and keep my commandments.
7 “You shall not misuse the name of the Lord your God, for the Lord will not hold anyone guiltless who misuses his name.
8 “Remember the Sabbath day by keeping it holy.
9 Six days you shall labor and do all your work,
10 but the seventh day is a sabbath to the Lord your God. On it you shall not do any work, neither you, nor your son or daughter, nor your male or female servant, nor your animals, nor any foreigner residing in your towns.
11 For in six days the Lord made the heavens and the earth, the sea, and all that is in them, but he rested on the seventh day. Therefore the Lord blessed the Sabbath day and made it holy.
12 “Honor your father and your mother, so that you may live long in the land the Lord your God is giving you.
13 “You shall not murder.
14 “You shall not commit adultery.
15 “You shall not steal.
16 “You shall not give false testimony against your neighbor.
17 “You shall not covet your neighbor’s house. You shall not covet your neighbor’s wife, or his male or female servant, his ox or donkey, or anything that belongs to your neighbor.”