Nicola Calipari's death was mourned across Italy
Nicola Calipari, 51, was shot dead at a US roadblock while escorting Italian journalist Giuliana Sgrena, who had been released by kidnappers in Iraq.
Italy and the US government disputed the circumstances of his death.
Italian prosecutors want a US marine, identified as Mario Lozano, to go on trial for the March 2005 killing.
DIFFERING ACCOUNTS US military: Car approaches checkpoint at high speed Troops attempt to tell driver to stop with arm signals, lights and warning shots Soldiers shoot into engine Italian government: No warning signs to motorists about impending checkpoint Car not speeding and did not accelerate after warning shots Proper inquiry impossible because vehicles removed and army logs destroyed just after shooting
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Last week Mr Lozano's court-appointed lawyer, Fabrizio Cardinali, said he expected his client to be tried in absentia for murder and attempted murder.
Last year Italy published a report into the shooting which conflicted with the US version of events.
The report blamed the troops' stress and inexperience, and said the US authorities should have signalled that there was a checkpoint on the road.
The report denied the US assertion that their military command in Baghdad was unaware of the Italian mission to secure the hostage's release, pointing out that the Italians had been allocated secure accommodation in an American-controlled area.
It said that the Italian car had been travelling at 40-50km/h, while the American version said it was going at about twice that speed.
The Americans insist that the car was going too fast and alarmed their soldiers.
The Italian magistrates say they are concentrating on ballistic evidence from the car. They say it was hit with three rounds; the second round which killed the officer was fired, they say, as the car was slowing down.
Their decision on Monday is likely to put further strain on relations between the two countries, the BBC's Christian Fraser reports from Rome.
The new Italian government has already stated its intention to withdraw troops from Iraq later this year and some of the comments they have made on the Iraq situation are said to have seriously irritated senior White House officials, our correspondent adds.
Nicola Calipari was fatally shot by U.S. troops at a checkpoint in Iraq in 2005
Italian prosecutors have asked a judge to indict a United States soldier for fatally shooting Italian intelligence officer Nicola Calipari at a roadblock in Iraq a year ago. The shooting occurred when Calipari was escorting the Italian journalist Giuliana Sgrena on her way to Baghdad airport. When their car came under fire from U.S. Marines at a roadblock, Calipari was fatally shot while trying to shield Sgrena, who was only lightly wounded in the incident.

The circumstances of the shooting are a matter of dispute between Italy and the United States. The U.S. military claims that the car was approaching the checkpoint at high speed, when the troops attempted to signal the car with light signals, aiming a green laser at the windshield and warning shots.  When the car failed to slow down, the soldiers shot into the engine of the car.

The Italian government claims that there were no warning signs prior to the shootings.  They contest that the car was speeding and that it accelerated after the first round of fire.  Moreover, they allege that a proper inquiry into the case was impossible since the vehicle was removed and army logs destroyed shortly after the incident.

Italian prosecutors are arguing that the shooting was a "political murder" as Calipari was a civil servant and the shooting damaged Italy's interests. In Italy, murder suspects cannot be tried in absentia unless the murder has political connotations. It is expected to take at least two months for a judge to rule on the indictment request.

The U.S. Embassy in Rome declined to comment.