Eight Iraqis arrested over Red Cap killings in 2003
The six men were all based at Goojerat Barracks in Colchester, Essex
Eight Iraqis have been arrested over the deaths of six Royal Military Police officers in 2003, the BBC has learned.
The Red Caps were killed by a mob in the town of Majar al-Kabir in southern Iraq while they were on a routine operation to train local police.
An Army spokesman said a judge had indicated there was enough evidence for the suspects to face trial.
"We are assisting the Iraqi government in every way possible to secure convictions," he added.
The six Red Caps killed included Sgt Simon Hamilton-Jewell, 41, from Chessington, Surrey, and Cpl Russell Aston, 30 from Swadlincote, Derbyshire.
Reg Keys: "It got to the stage where the families were going to go to the media themselves"
Cpl Paul Long, 24, from Tyne and Wear, L/Cpl Benjamin McGowan Hyde, 23, from Northallerton, North Yorkshire, L/Cpl Tom Keys, 20, from Bala, North Wales, and Cpl Simon Miller, 21, from Tyne and Wear, also died.
Cpl Aston's father, Mike, told the BBC: "We are cock-a-hoop, quite honestly. Those alleged killers murdered our sons in cold blood and we owe it to our sons to see that justice is done."
L/Cpl Keys's father, Reg, also welcomed the news. "We know for a fact that shortly after the Red Caps were killed there were Iraqi witnesses coming forward," he told the BBC.
"They were disgusted - some of the town elders - by what had happened and they gave the names of the alleged killers to the investigating team shortly after the killings.
"We kept saying, 'You know who they are. We know who they are. For goodness sake, do something about it.'"
L/Cpl Hyde's father, John, echoed their views, and said he was disappointed the accused men would not face the death penalty if found guilty.
Angus Crawford, BBC News
Some relatives of the dead were highly critical of the UK government for passing the investigation over to the Iraqi authorities.
There was a perception of a lack of political will and little faith in the Iraqi system.
But behind the scenes, UK and US special forces were involved in operations to track down the suspects.
If the cases do ever come to court, it will be a major test for the new Iraqi justice system. It will have to show the process is robust, fair and transparent.
But it is an opportunity to send a message that attacks on coalition forces do not go unpunished. For the families, it may at last give them some answers.
"Would it make me feel any better if they're convicted? No, it probably won't," he told the BBC.
"Before the British forces and British government passed on all the details of the investigation... the Iraqi government had to agree not to pass the death penalty... these people will serve jail sentences if they're found guilty."
A total of 16 arrest warrants relating to the murders have been issued by the Iraqi authorities since 2006. Eleven people have been detained, with three later released due to lack of evidence or mistaken identity.
An Army spokesman said: "The UK government is committed to seeing the killers of the six Royal Military Police personnel brought to justice and our thoughts remain with the families of those who died throughout this difficult process.
"The case is now at the investigative stage where the judge reviews the evidence. He has indicated that eight suspects now in custody will go to trial.
"This is good news and demonstrates the continued commitment of the Iraqi authorities to this case. However, we should recognise that referral to trial does not inevitably lead to a conviction."
The Iraqi criminal procedure involves two stages - an investigative stage and a trial stage.
During the former, a judge collects and reviews the evidence, often over a period of many months.
Sgt Simon Hamilton-Jewell, 41
Cpl Russell Aston, 30
Cpl Paul Long, 24
L/Cpl Benjamin McGowan Hyde, 23
Cpl Simon Miller, 21
L/Cpl Tom Keys, 20
The Army spokesman said: "We do not know how long this stage will take, and we must not unduly interfere with the Iraqi process.
"Officials in Baghdad and the UK are working to provide the judge with any supplementary information that he might require, including access to all RMP investigative material."
Once the case comes to trial, a panel of judges, rather than a jury, will examine the evidence before coming to a verdict, usually in a matter of days.
The BBC understands there is no start date in place for a trial because the investigating judge has initiated a search for new witnesses and issued a request to the Iraqi interior ministry for any police reports relating to the murders.
But a Royal Military Police liaison officer has been sent to Baghdad to help the judge interpret evidence provided by the UK.
The security situation in Baghdad is also believed to have affected the pace of the investigation.
The justice ministry was heavily bombed last October and staff forced to move into temporary accommodation. Baghdad's main courthouse also suffered damage in an attack in December.
An inquest into the Red Caps' killings in March 2006 found that the men had been given antiquated radios and inadequate ammunition.
But Coroner Nicholas Gardiner ruled that their deaths could not have been avoided.
However, the families of the men have called for an independent inquiry, arguing that negligence by Army personnel led to their deaths.
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