In Israel's Supreme Court building in Jerusalem, there is a room divided by a wall of reinforced glass. On one side sit the families of 13 Arab citizens of Israel shot dead last October by the country's police force; on the other, a panel of judges, court officials and witnesses, there to shed light on the events surrounding the deaths. Although both sides can see and hear each other through the wall, it might as well be made of concrete.

The Or Commission, a judicial inquiry into the deaths that began in February, halted its hearings for two months while the glass shield was built. The wall is designed to protect police officers from retaliation by the relatives of the dead after two were assaulted while in the witness stand.

The families were angered by a growing body of evidence suggesting the police carried out execution-style killings of the Israeli Arabs.

Although the nine-month intifada in the West Bank and Gaza Strip has reinforced a sense of Jewish solidarity in Israel, the inquiry led by Justice Theodor Or has been subtly undermining it.

The new barrier will do little to protect ordinary Israelis from a realisation that the hearings are rapidly turning into a trial, and it is not just the security forces in the dock. Inadvertently, the commission is raising a disturbing question: is the Jewish state a racist state?

The Or Commission was set up in the dying days of Ehud Barak's government in an attempt to win back Arab voters. It was charged with examining the events surrounding the deaths, as well as severe injuries to hundreds more Arabs, when police cracked down on protests in the Galilee area of northern Israel.

Mr Barak hoped the inquiry would prove police claims that riots by Israeli Arabs threatened neighbouring Jewish communities. It was also assumed it would vindicate the view of the Israeli media that the country's Arab citizens had finally been unmasked as a fifth column, violently supporting the uprising of their Palestinian cousins in the occupied territories.

Instead, a different picture has emerged. Most of the demonstrations, the inquiry has learnt, were contained within Arab areas, and in many cases the violence started only when police entered Arab towns and villages to quell the protests.

The force has admitted to the inquiry that it lied for months about its tactics. Not only did commanders fail to use riot control methods, such as addressing crowds through loudspeakers or arming officers with shields, but they resorted to rubber bullets and live ammunition almost from the outset.

An investigation by Ha'aretz newspaper shows the rubber-coated steel bullets were not the standard issue used by Israel's security forces; they were reserved for use by snipers against terrorists rather than for crowd control.

The police have yet to explain why live rounds were fired on a civilian population which, unlike the Palestinians in the occupied territories, was unarmed. One senior officer has told the inquiry it was the first time he had known of policemen being told to fire live ammunition at Israeli citizens.

But most shocking for Israeli Jews watching the daily television coverage has been evidence that in some areas police snipers were brought in to carry out what look suspiciously like executions of Arab demonstrators. The chief commander of the northern police force, Alik Ron, is himself implicated.

According to Mr Ron's original account, his officers shot at Israeli Arabs only when their lives were in immediate danger. But the snipers have provided a different version: in the town of Umm alFahm, for example, where three died, they have admitted they were stationed a considerable distance from the protesters.

Mr Ron, some have said, personally directed their shooting by radio, even though he was not in a position to see if his men were in danger. A senior officer who testified anonymously has told the inquiry Mr Ron also changed his instruction that only protesters endangering life were to be targeted, widening it to include anyone holding a slingshot.

Critics now accuse Mr Ron and his force of implementing a shoot-to-kill policy. Not surprisingly, the commission is being dubbed Israel's Bloody Sunday inquiry. The apparent similarities are so strong that lawyers representing the Irish families are advising the Arab lawyers in the Galilee inquiry.

Peter Madden, whose firm Madden and Finucane is representing nine of the 14 Irish families at the current Saville inquiry, said he had met lawyers from Adalah (Justice) earlier this year to offer advice on how to work with the commission. He believes they are facing an uphill struggle.

"It will be hard for the Galilee lawyers to get a proper hearing because Israel has not allowed them the right to cross-examine police witnesses," he said. "Israel is in effect breaking the international standards expected of a commission of inquiry."

That the police force dealt with the country's Arab population differently from the Jewish one is not in doubt. Individual officers have admitted they were told to use entirely different tactics when dealing with Israeli Jews who staged similar violent protests, often directed against Arabs.

In the worst incident, in Tiberias, where a policeman was killed during riots by Jews, officers had been ordered to leave their guns behind in their cars. Only batons and water cannons were used.

A British crowd-control expert who investigated October's events for Amnesty International says the police contravened both international standards and their own rules of engagement when they shot at Arab protesters.

Dr Stephen Males, a former assistant chief constable of Wiltshire, said: "The police failed in their policing role. They used weaponry and tactics more suitable for a military conflict. In this case the distinction between military and police strategies appears to have been ignored".

There has been plenty of evidence to support those who believe the police acted illegally during the events of last October. Last month the inquiry heard evidence from Hassan Asleh, whose 17-yearold son, Asil, was one of two teenagers killed in the village of Arrabe. Asil was well known for his involvement in campaigns to promote peace between Jews and Arabs.

According to witnesses, Asil was watching the protests from the roadside when he was chased by a police patrol. He ran into an olive grove where he stumbled and fell. As he lay on the ground, Arab witnesses say, a policeman stood over him and fired.

Doctors later found a bullet wound in the back of his neck fired from close range. At the inquiry none of the patrol officers could explain how Asil died. One, Ovadia Hatan, called the events in the olive grove "a mystery".

That an official attitude of suspicion and hostility towards Arabs exists in Israel is revealed by the hospital report on Asil's death; on its cover are stamped the words "Enemy Operation". Mr Asleh says: "If Asil was the enemy, it was because he was an Arab in a Jewish state".

Azmi Bishara, a leading Arab member of the Israeli parliament, says the police killings are evidence of a deep-seated racism in Israeli society that values Jewish lives above those of Arabs. "For 30 years or more the police and army in this country have been trained to treat all Arabs - including those inside Israel - as the enemy. We may be citizens, we are supposed to have equal rights, but in reality we know that we are not treated the same."

Mr Bishara's point has been underlined by the behaviour of Guy Reif, commander of the Misgav force that entered the village of Sakhnin, where two protesters were shot dead. After testifying to the inquiry he was arrested when it was revealed he had fired bullets at his own police station and thrown a grenade. Prosecutors believe he was trying to reinforce fears among Jews in the area that they were in danger from their Arab neighbours.

Apart from Mr Reif's case, there has been little effort on the part of the authorities to investigate the events in Galilee.

In the weeks following the clashes, no officials collected evidence of what happened at any of the locations where demonstrators were killed or injured. No post-mortems were carried out on victims except at Umm al-Fahm, and then only at the insistence of Arab lawyers who accompanied the bodies to hospital.

The reports were withheld until the inquiry ordered their release.

Even the inquiry has been criticised for taking a lacklustre approach to fact-finding. Much of the evidence presented to Justice Or has been compiled by Adalah.

Some of the most damning evidence they have collected, particularly from Nazareth, is just being considered, including video footage of two police snipers on a city-centre rooftop firing into the crowds below. At one point they stop to slap each other's hands in a celebratory "high-five" gesture.

Photographic evidence will also require explanations from the police. Lamp-posts and buildings in Nazareth are riddled with bullet holes almost uniformly at head height, despite police claims that officers were ordered to shoot only at demonstrators' legs.

Thousands of bullets collected and traded as if they are marbles by local children are, according to analysis by ballistics experts, spent live rounds fired from high velocity weapons.

Some liberal Jewish commentators hope the Or Commission may eventually heal the fracture in relations between Jews and Arabs in Israel. Few Arabs are as confident.

The new government of Ariel Sharon has already set its face against the inquiry. In May the public security minister, Uzi Landau, called the appointment of the commission a politically motivated "mistake" and strongly hinted that its recommendations would be ignored if they did not find favour with the police.

Whatever the outcome of the inquiry, the privileged position of the security forces in Israel is unlikely to be put in doubt. Service in the Palestinian occupied territories - and until recently in Lebanon - is a rite of passage for most Israeli Jews in which attitudes, particularly towards Arabs, are often shaped for the rest of their lives.

Mr Bishara's home near Nazareth was attacked by a Jewish mob on October 8th, in a backlash against the Arab protests earlier that week. Among the rioters was Ophir Elbaz, a policeman who had been on duty in Umm al-Fahm during the demonstrations. Although Mr Elbaz has admitted to the inquiry that he attacked Mr Bishara's and other Arab homes, and that at the time he was carrying his police gun, he has yet to be disciplined or suspended from the force.

Mr Bishara said: "How can we believe the Or Commission will begin to change the racism inside Israel when the authorities can't even take action against this single officer?"

Jonathan Cook is a freelance journalist who writes for the Egyptian newspaper, alAhram