The video of an Israeli soldier shooting a Palestinian in the head as he lay wounded and motionless on the ground confirms what Palestinians and human rights groups have been saying in recent months: Israeli security forces have shot and killed Palestinians who pose no threat. It's true that minutes earlier the Palestinian was one of two attackers who had stabbed another Israeli soldier in the West Bank city of Hebron. But the Israeli soldier is in stable condition after the attack. The Palestinian attacker was shot and wounded during the attack. But the incident did not end there. As the wounded Palestinian lies on the ground, slowly moving his head at one point, a soldier raises his rifle, cocks the weapon and fires. Blood is then seen streaming from the Palestinian's head. The Palestinian was soon declared dead. The Israeli military said the shooting was a "grave breach of IDF (Israel Defense Forces) values" and that a military police investigation has been launched. Defense Minister Moshe Ya'alon said Israel will deal with the case with "utmost severity". He said the shooting of the Palestinian "minutes after he was already neutralized and is lying on the ground is most grave and is in clear contradiction of the (military's) values and battle ethics". Fine words which ring hollow. Despite the evidence that the soldier shot a wounded man who had already been incapacitated, there is little optimism that the shooting will be properly investigated. Israeli forces have a long history of carrying out unlawful killings - including extrajudicial executions - in the occupied Palestinian territories with impunity. Amnesty International has documented a number of similar cases since the upsurge in violence began in October last year. In this latest case, Amnesty said the shooting of a wounded and incapacitated person, even if that person is the attacker, has absolutely no justification and must be prosecuted as a potential war crime. Additionally, just the act of detaining the soldier in this latest incident was described by an Israeli military spokesman as an "extraordinary" measure. The video was captured by a local Palestinian resident and distributed by the peace group B'Tselem. The military said the investigation began before the video surfaced but that is probably not true. Most Israeli media outlets initially went with the usual headline, "Soldier stabbed, assailants killed." A few hours later, however, the video of the incident was released. It's almost a sure bet that had the shooting not been recorded and had the video not been posted and gone viral, Israel would have remained silent about the incident, for fear of Palestinian reprisals and the worldwide condemnation it knows it will receive. Maybe even worse than the murder is the fact that no Israeli soldier in the immediate vicinity seems at all moved by it. Even though the incident is shocking, the blasé response of the other soldiers and security forces seen in the video is frightening in itself. That they are so unsurprised requires an investigation. This total apathy reflects not only the regularity of such incidents but also the culture of impunity in which IDF soldiers feel free to shoot and kill Palestinians against the IDF's own rules of engagement. Since October, Israeli security forces have been unnecessarily killing Palestinian suspects. Israel has consistently denied the practice but the numbers speak for themselves. Since October, 29 Israelis have been killed. In that period, the Israeli army has killed at least 206 Palestinians, including protesters, bystanders and alleged attackers. Israel is using excessive force and killing assailants who have already been stopped or wounded. What happened in Hebron was one more example. A Palestinian man was already shot and lying on the ground wounded, presenting absolutely no threat to anyone at the time he was murdered. What happened was a public execution.