Updated

Israel's military justice system is in the spotlight as it investigates a soldier caught on tape shooting to death a subdued Palestinian attacker, a case that has polarized the nation.

While the military has stressed that its courts are independent, critics say the system has a poor record of punishing errant soldiers, perpetuating a culture of impunity. They say the same result is likely for the soldier, who is expected to be formally charged in the coming days.

The shooting took place last month in Hebron, the volatile West Bank city that has been a focal point of the latest, 7-month wave of Israeli-Palestinian violence. The military initially said two Palestinians stabbed and wounded an Israeli soldier before troops shot and killed the pair.

In a video later released by the Israeli human rights group B'Tselem, one of the attackers was shown still alive after the initial shooting. The video, taken by a Palestinian volunteer for the group, shows the wounded attacker lying on the ground, slowly moving his head. About a minute later, a soldier raises his rifle, cocks the weapon and fires. Blood is then seen streaming from the Palestinian's head.

An autopsy determined the bullet to the head was the cause of death.

During the current wave of violence, the Palestinians have accused Israeli security forces of using excessive force against attackers who have already been stopped or wounded. Of the 188 Palestinians killed during the outburst, Israel says 142 were attacking or trying to attack Israelis, with the rest killed in clashes. A handful of amateur videos supporting the Palestinian claims have emerged, but the Hebron killing was perhaps the clearest so far.

The incident triggered an uproar in Israel, with the country's defense minister, military officials and many Israelis calling it contrary to the army's values. That outcry in turn kicked up a counter-torrent of support for the soldier, with many calling his actions appropriate for a country reeling from months of Palestinian attacks, mostly stabbings, that have killed 28 Israelis and two Americans.

Prime Minister Benjamin Netanyahu, initially critical of the soldier, later softened his opposition in a nod to his nationalist constituents.

Critics say only accountability can promise deterrence and prevent excessive force from being used against Palestinians, even if they are attacking Israelis. Few soldiers have been punished for their alleged roles in crimes against Palestinians, prompting criticism of the system.

"An investigation has to be independent, effective, could lead to actual measures, has to be timely, transparent and has to be fair and unbiased," said B'Tselem spokeswoman Sarit Michaeli. Israel's military justice system "simply does not adhere to these standards," she said.

Citing official army figures, the Israeli rights group Yesh Din said that of the more than 2,600 investigations opened by the military into alleged crimes committed by soldiers against Palestinians between 2000 and 2014, only 136, or 5 percent, resulted in indictments, leading to 193 convictions. More than one soldier can be listed in a single indictment.

Wary of Israeli self-investigation, the Palestinians have turned to the International Criminal Court. One of the criteria for the ICC to intervene would be if Israel's justice system were deemed insufficient. Israel says its system is fair and independent, but B'Tselem and the Palestinians say Israeli investigations are merely a front to thwart an external inquiry.

The military insists the system works, saying the low indictment rate does not signal lack of effort. They say the system is independent and that proper measures are taken if there are legal grounds to try and punish a soldier. Early this year, for instance, two soldiers were jailed for seven and nine months for physically abusing Palestinian prisoners.

"It's true there aren't a lot of cases, but that's not because they are avoiding prosecuting soldiers on purpose," said Emmanuel Gross, a former military judge.

The soldier involved in the Hebron shooting was swiftly detained after the incident and is being investigated for manslaughter. According to media reports, the soldier said he opened fire because he feared the subdued attacker was wearing an explosive belt and still posed a threat.

The investigation into the soldier, whose name is barred from publication, is the first opened by the military since the violence erupted last September. Israel's Justice Ministry, which probes police, has launched one investigation into the shooting death of a 16-year-old Palestinian girl who was killed by a police officer as she lay wounded after stabbing a man with scissors.

Israeli authorities say they launch criminal inquiries into such cases if the situation warrants one and take further action as needed.

Israel has come under fire for not punishing soldiers before. It has not convicted any troops involved in alleged misconduct from the 2014 Gaza War. Of some 300 alleged incidents reported by Palestinians, rights groups or the media, it has opened about 30 criminal investigations and indicted three soldiers for looting.

The military last month closed a case looking into the shooting death, captured by a security camera, of a Palestinian protester in the West Bank in 2014, saying there wasn't sufficient evidence. A paramilitary border police officer was charged with manslaughter in the death of another Palestinian from the same demonstration. Another instance of a soldier who killed a rock-throwing protester was also recently dismissed, drawing condemnations from human rights groups.

In the current case, criticism against the justice system has come not only from rights groups but also nationalist Israelis. The soldier's supporters see the court proceedings as an affront to all Israelis who send their sons and daughters to compulsory military service.

The heated public debate prompted the military attorney general to defend the justice system.

"The military justice system enjoys complete independence," Brig. Gen. Sharon Afek told a legal conference. "We are committed to represent the public interest ... with integrity, openness to criticism and an aim to improve."