Could death be a half-truth? This question is obviously a killer's last hope and best alibi. There is enough truth in that great genre of mystery fiction to suggest that murder can often be an open debate. This does not help the dead, for there can be no murder without a victim; but this remains a serious concern for the living. Whether murder is committed in cold or warm blood, there is no legitimate end without justice.

The pictures depicting the killing of a 12-year-old child, Balachandran, in Sri Lanka, were stark. The chubby innocence of his face was a further torture to the imagination. His only mistake was being son of the wrong parents, as far as his killers were concerned. His father was Prabhakaran, the defeated and slain dictator of the LTTE, who spent his life trying to partition Lanka and create a separate country for its Tamils. No war is pleasant, but this one was especially ruthless. Balachandran became a hostage after LTTE's annihilation in the winter of 2008-09. Channel 4, the British TV station, which has been running a campaign against human rights violations by the Lanka Army, aired footage of this murder and alleged that orders had come from the very top.

The official Lanka Army reaction, through a spokesman, called the story "lies, half-truths and…speculation."

If that is only half the truth, then what is the other half?

The only speculative part is the bit about orders coming from the very top but that is common sense even if the source has not been identified. No officer would risk elimination of such a high-profile prisoner without clearance from the highest in the land. Twenty four hours later, someone more intelligent in the Lanka government added that the visuals had been morphed. The channel explained that it had verified the images.

But there is a simpler answer. If the pictures are a lie, then the child must be alive. If he is alive, he is in Lanka government's hands. All the authorities have to do is produce the child. That would be the ultimate habeas corpus: produce the body, in this case hopefully alive.

That is unlikely to happen. What will follow is silence, tons of it, in the quiet confidence that media stories cannot be repeated forever. This silence is being, and will be, supported by the three major powers with an interest in Sri Lanka: India, China and the United States. No one will seriously question Colombo at a Geneva human rights forum, or weaken relations with the present government which took the decision. They will endorse the logic of this murder. Colombo has killed the child for one reason, and one alone: that he should not survive to wear his father's mantle ten or fifteen years later. An extra-judicial exit was the only "solution." Delhi, Beijing and Washington are not terribly squeamish when it comes to present or future terrorism. One false word and their own skeletons will clang noisily, awakening all sorts of demons in Geneva and elsewhere.

As in any conventional murder mystery, the killers did overlook an obvious detail, the sort of clue that sets the grey cells of a Hercule Poirot whirring at a frantic pace and opens up the path of discovery. Colombo's wise men missed one of the great new facts of the contemporary age, the rise of the mobile phone.

All the mass manufacturers of such phones are as much camera makers as communication specialists. Everyone is now a walking camera. We are still groping through the full implications of this mobile phone revolution, but one thing is already clear: justice has moved from the time of eye-witness testimony to camera-witness evidence. We are undecided about CCTV surveillance. When there is a terrorist attack we want them everywhere. In calmer times we worry about government snooping into our private lives. Perhaps there is no such thing as privacy anymore already. Telephone conversations are routinely taped by secretive agencies.

Governments have other worries. Any official today can take out his camera phone and copy a file in a second, exposing corruption if he so wishes, or simply waiting for the opportunity to indulge in some supplementary blackmail of his superiors on the side. Almost every event is being recorded, sometimes with a sense of celebration, sometimes out of a sense of grievance. We get antsy at the thought of a barbarian government assaulting our privacy. But the anonymous individual can be a greater danger.

There are two ways the footage of Balachandran's killing could have reached media. Someone could have leaked it from government records. Or it might be a soldier in the death squad who thought he wanted a gruesome but historic memento, and then began to grapple with his conscience. We do not know, yet. But something slipped through that security net, and it was not a lie.

The writer is Editor of The Sunday Guardian, published from Delhi, India on Sunday, published from London and Editorial Director, India Today and Headlines Today.