On May 15, two Palestinians were killed in the village of Beitunia, north of Jerusalem. The 17 year-olds were taking part in a stormy demonstration marking Nakba Day, when simultaneously Israel gained independence and Palestinians were uprooted from their land and became refugees.

The medical reports from the Palestinian hospital in Ramallah determined that the two were killed by live ammunition. Their families blamed Israel's security forces.

Israel’s military spokesman was quick to declare unequivocally: No live fire was used during the incident. Up to that point - a routine event, similar to hundreds of others during decades of Israeli occupation.

But unlike previous events, security cameras at the scene documented the killing of Nadim Nuwara and Mohammed Salameh. TV crews also filmed the events.

Nawara's family agreed to an autopsy in the presence of a Palestinian coroner, the head of Israel's forensics institute and pathologists from abroad. The results of the post-mortem were unambiguous: Nawara had been killed by live ammunition. The shrapnel and a bullet lodged in his backpack were handed over for forensic examination to the Israel Police laboratories.

The Israeli army kept insisting that its soldiers had not fired live bullets, hinting that perhaps the Palestinians themselves had used live ammunition. "This footage has been edited," the army responded. "There was no live fire [from our side]." Defense Minister Moshe Ya'alon told reporters: "I know this practice of editing videos."

In briefings to journalists the army suggested that Nuwara’s outstretched arms indicated he was faking his fall; this narrative was adopted and expanded by several journalists who indicated he was actually a gifted actor.

Six months later a border policeman was arrested on suspicion of using live ammunition. Last week he was indicted for killing Nawara. His direct commander was questioned on suspicion of helping to cover up and/or whitewash the use of live fire.

We have to acknowledge that the policeman is still presumed innocent until proven guilty. There is a gag order on most details of the case.

But even when the accused is brought to justice, the trial will not deal with all aspects of the case, not least with the security forces culture that enabled a soldier to use live ammunition and not to report it, perhaps even to lie, and with the climate that allowed the soldiers around him, including, allegedly, his commander, not to report it.

The trial will not address the IDF's automatic denial of claims by Palestinian and human rights organizations. This automatic, derisive response casts doubt on any claim and even evidence emanating from the Palestinian side. The IDF's reaction in this case was so quick and unequivocal, that it left no apparent room for doubt, despite the absence of any in-depth examination of events.

The trial will not deal with the derogatory declarations of the minister of defense who derided the security camera footage.

The trial will not address the issue of the journalists so quick to adopt without a shred of doubt the Israeli military’s version of events and launched an all-out campaign on their behalf, going as far as to cast doubt on the very deaths themselves.

The trial will not deal, either, with military norms that enable spokesmen to respond without investigating, that enable soldiers to disobey orders and that too often result in security forces that are trigger-happy when facing Palestinians.

The trial will not address how the political echelons feel no need to rush to examine events, to collect evidence on the ground before it disappears for good, no real need to provide satisfactory answers for the death of a Palestinian, because it’s only another Palestinian who was killed. All these things will not be examined in any trial.

This is the climate that enables tens of thousands of Israelis to launch a social media campaign in support of the detained policeman. Do they support live fire against unarmed Palestinians? Are they in favor of a whitewash?

This saga exposes two failures that have become routine: A substandard investigative system that does not aim to reveal the truth, by not examining seriously the soldiers who were present, nor collecting evidence from the scene in real time, or taking testimony from Palestinian witnesses. And this failure is accompanied by an aggressive public relations campaign that does everything in its power to undermine the claims of Palestinians and human rights groups.

And then, when a combination of circumstances - strong evidence, stubborn insistence by Palestinians and human rights groups and external experts – all manage to put together a volume of proof that cannot be ignored, and the investigation nets results, everyone is surprised. That is the exception to the rule, when it should really be the norm.

Anat Saragusti is the director of B’Tselem USA, The Israeli Information Center for Human Rights in the Occupied Territories.