After preliminary motions, the trial was adjourned until May 14 for procedural reasons.
U.S. National Guardsman Mario Lozano denies wrongdoing in firing at Nicola Calipari's car when the agent was escorting a newly freed hostage to Baghdad airport in 2005.
Lozano says the driver ignored warnings to slow down or stop. He is being tried in absentia because Washington has ruled out handing him over.
(compiled from agency reports)