The start of the trial that accuses a US soldier of voluntary homicide will be a painful experience for Italian journalist and former hostage Gilliana Sgrena.

Sgrena was held for 28 days in Iraq but there were no scenes of joy as she returned to Rome, nursing a gunshot wound to the shoulder.
Italian intelligence agent Nicola Calipari was killed in the shooting, when an American patrol opened fire on their car.

Calipari had been responsible for Sgrena's release and was hailed as a hero by Italian press.

US Army National Guard Mario Lozano will face trail in Rome for the death of Calipari - with the trial taking place without Lozano present as the US government refuses to hand him over.

Sgrena says many memories will be revived by the trial.

"It is a mixture of anguish and of hope. Of course I wanted this trial, I am very happy it will start. But of course for me it means to go back to two years ago and what happened two years ago."

The incident took place as Sgrena and Calipari headed towards Baghdad airport and freedom.

Both the US and Italian governments have said the shootings were an accident.

PHOTO CAPTION

Italian intelligence officer Nicola Calipari speaks on a mobile phone in an undated file photo. (Reuters)