While the deaths of four young men from the same extended family was a tragic result, it was not the result of negligence or any other criminal action on the part of the Israel Defense Forces. The boys were located in an area that was used exclusively by Hamas terrorists, and specifically where Hamas naval commandos gathered to prepare attacks against Israel; those figures seen via aerialSURVEILLANCE were reasonably understood to be militants preparing to attack Israel. 

The Israel Defense Forces' Military Advocate General announced today, June 12,  2015 his conclusions regarding a tragic incident from last summer's OperationPROTECTIVEEdge, in Gaza:

While the deaths of four young men from the same extended family was a tragic result, it was not the result of negligence or any other criminal action on the part of the Israel Defense Forces. The boys were located in an area that was used exclusively by Hamas terrorists, and specifically where Hamas naval commandos gathered to prepare attacks against Israel; those figures seen via aerialSURVEILLANCE were reasonably understood to be militants preparing to attack Israel.

In that incident, on July 16, four Gazan boys died as the result of an air force strike on the Gaza Beach. The four boys, Ahed Atef Bakr, Zarakiya Ahed Bakr, Mohammad Ramiz Bakr and Ismail Mahmoud Bakr, had allegedly been playing hide and seek{The original Hamas/ United Nations information release claimed that they had been playing soccer]on the beach when it was struck by IAF rockets.

The Israeli military police carried out an extensive criminal investigation into the incident.

As was explained by IDF spokesperson Lt. Col. Peter Lerner, testimony and other evidence was gathered and extensively examined:

Testimonies were collected from a large number of IDF soldiers and officers who were involved in the planning and execution of the attack. Additionally, an extensive number of documents relating to the attack were reviewed, along with video footage documenting the attack in real time, as well as media images and video footage which documented parts of the incident. Efforts were made to collect the testimonies of Gaza Strip residents who were, allegedly, witnesses to the incident. In this context, the collection of testimony from three witnesses was coordinated. Regretfully, despite the prior coordination, the witnesses eventually declined to meet the investigators, and instead provided affidavits in regard to the incident.

The investigators learned, through analysis the collected evidence, that the very place where the Bakr victims were struck is an "area that had long been known" as a Hamas's Naval Police and Naval commandos' Compound which was "utilized exclusively by militants." [and as had been reported at the time shortly before the area was struck it was used as a launching location for rockets against Israel].

In addition, the area in which the Israeli rockets hit was "closed off by a fence and clearly separated from the beach serving the civilian population." In addition, through affidavits provided by Palestinian Arab witnesses, amongst other sources, the compound "was known to the residents of the Gaza Strip as a compound which was used exclusively by Hamas's Naval Police."

A number of IAF attacks on the compound had taken place prior to July 16, during which a shipping container used to store military supplies and as a Hamas "command and control center" was hit. The Israeli intelligence determined that "operatives from Hamas's Naval Forces would gather in the military  compound in order to prepare for military activity against the IDF."

And so, when Israeli aerialSURVEILLANCE identified a number of figures entering the compound at a running pace, and those figures "entered a shed adjoining the container which had been attacked the day prior," the Israelis reasonably believed those figures "to be militants from Hamas's Naval Forces, who had arrived at the compound in order to prepare" to attack the IDF.

The four figures "were not identified at any point during the incident, as children," nor could they have been identified as such at any time, via aerialSURVEILLANCE.

It was with this set of circumstances and information that "all the necessary authorizations for an attack had been obtained," and the location wasTARGETED.