WHERE MEDICAL EVIDENCE IS NECESSARY:
Where ‘A’ deals a fatal blow on ‘B’, say with a club or iron rod, and ‘B’ immediately collapses and dies as a result of the blow, it is quite easy to conclude that ‘A’ caused the death of ‘B’, the cause of death can properly be inferred that the wound inflicted caused the death. Now a more detailed scenario might be problematic to the prosecution and the Court.
Say: ‘A’ cuts ‘B’ on the arm with a sharp knife, ‘B’ does not seek medical attention to treat the cut but rather opted for self-medication, and subsequently, the cut led to an infection, and ‘B’ dies after a few days. Now it is not an issue that the first element has been satisfied (that B is dead); rather, can it be said that A caused the death of B? This could only be proved with the aid of medical evidence (expert opinion) to the effect that B’s death could only have occurred and did in fact occur through the cut inflicted by A. As a matter of fact, A could have died from pneumonia, or through other means, the prosecution in this scenario would be throwing away their case without involving a post-mortem result or the involvement of a medical expert to the effect that A in fact caused the death of B. Causation can only be established through medical evidence in this respect.
The principle of causation or link in a criminal charge of murder is to the effect that the prosecution must show that the initial assault, attack, or act of the accused person in a criminal case was or is responsible for the subsequent death or demise of the person attacked, or caused injury though the person did not die immediately or so, soon after the unlawful act of the accused person. Where there is a break in the chain of causation, then the second element fails and the accused person must be acquitted. This was accorded judicial favour by the Supreme Court in IKONO V. STATE (2021) 13 NWLR (Pt. 1792) 185 @ 203-204, paras. E-C, wherein the Court submitted thus:
“In order to hold an accused person criminally responsible, the chain of causation must not be broken. Once there is a broken link in the chain of causation, that broken link must be resolved in favour of the accused as it affects the actus reus of the offence. In other words, where the injury which caused the death is not the proximate, legal or direct cause of the death of the deceased, the benefit of the doubt must be given to the accused. Again, where there is more than one possible cause of death, the benefit of the doubt must be given to the accused because the available evidence in such a situation would not pin the accused down to the death of the deceased. This is because there is an intervening or supervening cause, in Latin expressed as novus actus interveniens and nova interveniens respectively.