In Genesis 9:6, God clarified by special revelation that mankind has the authority and duty to put murderers to death. This authority is not exclusively given to a subset of humanity called “rulers” or “the civil magistrate.” Rather, it is given to all image bearers. This is confirmed in the law of Moses, which authorizes individuals to administer this vengeance according to the principle of lex talionis (see The Avenger of Blood).
On the first page of Lex Rex, Samuel Rutherford notes his disagreement with “the Brazillians, who teach that every single man hath the power of the sword to revenge his own injuries, as Molina saith” referring to the law practice of native South Americans, which received a great deal of study at the time. Of course, Rutherford must reject this concept of authority in order to justify his belief in the civil magistrate as a father set over his children (the nation) to chastise and discipline them. If all image bearers have authority to administer justice by the sword, then such fatherly chastisement is no part of the administration of justice by the sword.
Below is an excerpt from a 1933 article in the American Bar Association Journal titled A Case of Lex Talionis.
Account of a Trial in One of Our Own Courts of Record in Which the Offense Charged in the Indictment Consisted of Killing a Man in the Asserted Exercise of This Ancient Right – Defendant Was Oshkosh, Head Chief of the Menominee Tribe of Indians – Trial Took Place in 1830, in What Is Now Green Bay, Wisconsin, but Was Then Part of Territory of Michigan – Prominent Figures in Early Wisconsin History Who Took Part
When we say that a man has “taken the law into his own hands,” we use a phrase which, though we may not trouble to analyze it, has a double implication. For it implies that he has done, either by obtaining redress from, or inflicting punishment upon, a wrong-doer, that which in substance is right according to the prevailing judgment of mankind. But it also recognizes and implies that what he has done is unlawful, because the law does not permit him to enforce his own rights, or to be the judge of his rights and those of another, and to execute his decisions. And of course, we do not stop to think that there was a time when every man did take the law into his own hands, and that the law itself, that is the primitive rules of the time which roughly served the purpose of law, recognized his right to do so, and provided no other means of redress. That time is in the very remote past, before mankind had fairly started on the long, long road which has led from the individual action of mere barbarism to the orderly enforcement of public and private rights by a judicial trial and decree determining the rights of the parties and the methods of their enforcement. We are used to these methods, and approve them, even when we see that in individual cases the right does not always prevail, and that wrong goes unpunished. We know that these methods, though not perfect, are a part of what has been attained by that which we call a government of law and not a government of men.
In the primitive society, to which indeed the word, ”society,” can hardly be applied with accuracy, every man necessarily took the law into his own hands: for there was nothing which really answered to what we now call a state to act for him. The right of redress for an injury to or property which we now term, “the right of action,” rested in the injured person. And it was truly a right of action and not merely the privilege of bringing a legal action in a tribunal. It was for him to determine how he would enforce his right, either by securing compensation, or by doing violence to the wrong-deer: for if he took no action nothing was done about it.
As an injury to one member of a family usually in some degree injured all members, both the right and the obligation to take action was gradually extended to everyone in the family and for the benefit of the family. And as men became more closely associated and learned the benefit of concerted action, it was in extended to the tribe or district in which the injured person resided. From this loose method, there finally arose ‐ and “finally” in such matters means a very long time – the conception, and then the practice, of separating the right of redress from the right of punishment, leaving the former in the injured person and the latter in whatever form of organized society existed. The government, or state, could exercise its punitory right either by fine, or by imprisonment or death, leaving the injured person to collect the compensation due him for his private injury. But when this point was reached in the process of developing law it was recognized that he was not to “take the law into his own hands,” but was entitled to and must seek the aid of the government through its courts; and that any fine which the state collected by way of punishment belonged to it and not to the person who had suffered the injury.
This primitive conception of justice and its enforcement existed wherever primitive man found his dwelling. And the regard which the Ameriam Indian had for this old lex talionis is shown by the speech of a Chippewa Chief to Alexander Henry. one of the pioneer English fur traders, when he came to Michilimackinac in the fall of 1761. In the French and Indian War, which had been finished by Wolfe’s capture of Quebec, these Indians had been allies of the French and had fought on their side. They still retained their feeling of loyalty to the French crown. and of hostility to the English, whom they still regarded as their enemies, notwithstanding the Treaty of Paris by which peace had been concluded between France and England, and France had ceded to England her Canadian possessions. They resented the presence of Englishmen at this strategic place by which France had once held control of the western fur trade; and in explaining their feeling and its origin, their Chief, who bore the rather musical name of Minavavana, made a long address to Henry, in the course of which ‐ as preserved in Henry’s account ‐ he said:
“Englishman, our father, the King of France, employed our young men to make war upon your nation. In this warfare many of them have been killed; and it is our custom to retaliate until such time as the spirits of the dead are satisfied. But the spirits of the slain are to be satisfied in either of two ways; the first is by the spilling of the blood of the nation by which they fell; the other by covering the bodies of the dead, and thus allaying the resentment of their relations. This is done by making presents…”
The ancient right of a member of a family or tribe to kill a man who had killed one of his family or tribe of course had nothing to do with the law of self defense. It was not, and indeed in the nature of things very rarely could be, exercised in connection with the original killing out of which the right arose. It was strictly what the Latin name, “lex talionis,” implies ‐ the law of revenge. And as it has so long been disused that the fact that it once existed has been forgotten, we may view with surprise the discovery in one of our own courts of the record of a trial  in which the offence charged in the indictment consisted in the killing of a man in the asserted exercise of this ancient right.
[T]he defendant [was] Oshkosh, the head Chief, or Grand Sachem of the Menominee tribe… An Indian named O-Ke-Wa was paddling along a stream known as Devil River, or Hell Creek, when he saw something moving in the bushes. Under the same impulse of unutterable folly which sometimes induces green hunters of our own time to think that anything which moves is a deer, he acted upon that assumption and, picking up his rifle, sent a bullet which killed a Menominee Indian. Whereupon Oshkosh, with two companions of his tribe went at once to the wigwam of the guilty person and killed him with their knives.
Now it will be seen that though the shooting of the poor Indian, who was probably picking berries, or perhaps was himself looking for a deer, was an act of indefensible carelessness, the result was really nothing but an accidental death. But perhaps we should also remember that the laws of several states now require a hunter, at the peril of indictment, to know the difference between a man and a deer, and to do his shooting in the light of that knowledge. The act of Oshkosh and his accomplices was, however, done with the deliberation which prerncditation inspires.
The Chief appeared, clad in the full panoply of his native dress as Sachem of his tribe. and conducted his own defense through an interpreter without the aid of counsel. He stood there in court representing the age long past of the race which once owned not only the forest, of whose tree trunks the walls of the rude court house were framed, but the whole domain of America’s forest, plains, rivers and lakes from ocean toocean. And he also represented, and asserted as his defense, a rule of primitive law which once existed in the primal customs of all races and which he claimed was still in force in his native land, and was a justification for his act.
[The jury stated:]
“…[T]he said AshKosh did kill and slay the said Okewa in pursuance of the said Indian Law and usage, claiming at the time his right so to do that alter the said OKewa had killed the said MasKiwete; he the said AshKosh did allege that the laws of the White People, meaning the laws of this Territory, were of no validity in regard to the matter and not binding upon any Indian of the said tribe in this behalf…
Whereupon all and singular the premises being seen and by the Court here fully understood it is considered that the said AshKosh of and from the felony and murder so as aforesaid charged against him be wholy aoquited and discharged.”
What are we to make of this incident and trial? Was OshKosh justified in executing Okewa? First, Scripture clearly teaches that this act of vengeance is not reserved for rulers. It is a right and duty of all image bearers. Thus OshKosh was justified in “taking the law into his own hands.” However, Deuteronomy 19:6 says that in the case of an accidental killing, the killer “is not deserving of death, since he had not hated the victim in time past.” Therefore OshKosh was not right to execute Okewa. However, the law of Moses also prescribes that due process be established to deal questionable incidents such as accidental killings.
Numbers 35:11 you shall appoint cities to be cities of refuge for you, that the manslayer who kills any person accidentally may flee there. 12 They shall be cities of refuge for you from the avenger, that the manslayer may not die until he stands before the congregation in judgment... 22 ‘However, if he pushes him suddenly without enmity, or throws anything at him without lying in wait, 23 or uses a stone, by which a man could die, throwing it at him without seeing him, so that he dies, while he was not his enemy or seeking his harm, 24 then the congregation shall judge between the manslayer and the avenger of blood according to these judgments. 25 So the congregation shall deliver the manslayer from the hand of the avenger of blood, and the congregation shall return him to the city of refuge where he had fled, and he shall remain there until the death of the high priest who was anointed with the holy oil.
If this process is not established and the manslayer (not murderer) does not seek asylum for trial, then he is without protection from the avenger of blood.
Numbers 35:26 But if the manslayer at any time goes outside the limits of the city of refuge where he fled, 27 and the avenger of blood finds him outside the limits of his city of refuge, and the avenger of blood kills the manslayer, he shall not be guilty of blood, 28 because he should have remained in his city of refuge until the death of the high priest.
Thus the jury was correct in deciding that OshKosh was not guilty of murder. This is a very interesting concession in Scripture to the imperfection of human justice. God prescribed procedures for Israel to follow in the land (which all nations can learn from and implement according to wisdom). This type of incident between OshKosh and Okewa is the perfect setup for a never-ending blood feud between tribes, as was common. It was an accident followed by an unjustified retaliation, which would seem to warrant a justified retaliation in turn, ad naseum. Thus God established that if the manslayer does not flee for refuge to the designated place to await trial, his death may not be avenged. Thus we can see that God provided checks for the imperfect practice of justice among men. The Indians did not appear to have any kind of refuge process established, thus leading to these kind of problems. However, when the “White People” established due process, they mistakenly revoked the right of the avenger of blood. Scripture provides the correct balance.
Note also that Scripture corrects another practice of the Indians mentioned above with regards to lex talionis. Minavavana said that the English could make retribution by giving a present to the Indians. This was common in many cultures. But God strictly forbids this in the case of murder.
Numbers 35:31 Moreover you shall take no ransom for the life of a murderer who is guilty of death, but he shall surely be put to death. 32 And you shall take no ransom for him who has fled to his city of refuge, that he may return to dwell in the land before the death of the priest.
Scripture provides the spectacles we need to correctly understand the imperfect administration of justice in this fallen world – correcting both modern “civilized” law and ancient “uncivilized” law.
Finally, note the author’s recognition that historically the right of redress and vengeance rested in the injured party and that somewhere along the line the state (unjustly) monopolized that right for themselves. The result was that “any fine which the state collected by way of punishment belonged to it and not to the person who had suffered the injury.” Sounds like quite the racket. Scripture doesn’t teach any kind of “justice” like that.