The US military has confirmed that it will not discipline soldiers who shot dead an Italian agent in Iraq as he escorted a freed hostage to safety.
Nicola Calipari's death was mourned across Italy
The US said its soldiers had acted within the rules of engagement and that the death was a "tragic accident".
Nicola Calipari died to protect Italian journalist Giuliana Sgrena as their car came under US fire near Baghdad.
Italy has refused to endorse the official report's conclusions and is pressing ahead with its own inquiries.
"The [...] investigation concluded that the vehicle approaching the checkpoint failed to reduce speed until fired upon and that the soldiers manning the checkpoint acted in accordance with the rules of engagement," the US military said in a statement.
The report also said that the death might have been avoided if the US had been aware of Italian plans to release Ms Sgrena.
"Prior co-ordination might have prevented this tragedy," Brigadier General Peter Vangjel wrote in his report.
Prime Minister Silvio Berlusconi, one of US President George W Bush's staunchest allies, has said he will address parliament on its findings next week.
The death of Mr Calipari caused public outrage in Italy and intensified pressure on Mr Berlusconi to pull Italian troops out of Iraq.
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: Italy makes all necessary contacts with the US for safe passage
The driver stops immediately when a light flashes 10m away
At the same time, shots are fired into car for 10-15 seconds
Italian investigators who collaborated with the joint probe are also expected to publish their own version of events in a few days.
A separate Italian criminal inquiry into the incident continues.
Italy and the US have long disagreed on what happened as Mr Calipari's car approached a checkpoint on a road towards Baghdad airport.
The military said the car in which Mr Calipari and Ms Sgrena were travelling was speeding as it approached a temporary checkpoint and failed to heed warning signals to stop.
Ms Sgrena, who was hurt in the shooting, said the car had not been speeding and that there had been no warning before the troops opened fire.