The burden of proof in self-defence
In all cases where the evidence discloses a possible defence of self-defense, the onus is on the prosecution to prove that the accused did not act in self-defense.
In Manzi Mengi v R [1964] 1 EA 289
The appellant found cattle on his shamba being tended by two children who claimed that the deceased had told them to bring the cattle there.
The appellant drove away from the cattle and went to fetch a panga to repair the fence. On his return, he found the cattle there again and the children told him that they had brought the cattle back on the deceased's instructions.
The appellant again drove away the cattle. While he was repairing the fence the deceased appeared armed with a bow and arrows and after abusing the appellant threatened to kill him. He then fired an arrow at the appellant but missed.
The appellant then told the deceased not to kill him and the deceased replied I am going to kill you.
The deceased then crossed the fence and entered the shamba and struck the appellant twice with the bow and tried to stab the appellant with the arrows whereupon the appellant struck the deceased repeatedly with the panga as a result of which the deceased died.
When charged with murder the defence of the appellant was that he had acted in self defence to save his life.
The trial judge found that the appellant stood in danger of his life, that if he had not made use of the panga, the deceased would probably have killed him and that the appellant had acted in self-defence but had used excessive force.
The judge accordingly convicted the appellant of manslaughter.
Held: That the onus was on the prosecution to show that the appellant was not acting in self-defence; it was for the prosecution to show that there was a time before the fatal blow was struck for the appellant to have realized that he was out of danger and desisted; this onus was not discharged.
Effect of the defence
Where self-defence has been established successfully, the accused will be acquitted.
The case in point is Manzi Mengi v R [1964] 1 EA 289.
However, where the accused killed in self-defence but used excessive force, he or she will be convicted of manslaughter.