Last Updated Aug 27, 2014 6:30 PM EDT
WASHINGTON - A prosecutor told a federal jury on Wednesday that four Blackwater guards unleashed a hail of gunfire on more than 30 innocent Iraqi civilians seven years ago, leaving "bloody, bullet-riddled corpses" at Nisoor Square in downtown Baghdad.
In closing arguments at the guards' trial that began in June, prosecutor Anthony Asuncion said the four defendants "took something that didn't belong to them" - the lives of human beings and the health of others who are still suffering from their wounds from the Sept. 16, 2007 shootings.
The jurors' job "is a search for truth" in the wake of violently shattered lives, he said.
The defense, however, contended that the guards were acting in self-defense after coming under fire from insurgents.
The U.S. government brought charges against the defendants in 14 of the deaths and 18 of the non-fatal shootings.
One defendant, Nicholas Slatten, faces a first-degree murder charge. Defendants Paul Slough, Dustin Heard and Evan Liberty are charged with voluntary manslaughter, attempted manslaughter and gun charges.
Slatten could be sentenced to life imprisonment if convicted. The others face mandatory minimum sentences of 30 years in prison if convicted of the gun charge and one other count.
A defense attorney told the jury Wednesday that Iraqi national police removed evidence that would prove Blackwater security guards were being fired on by insurgents, prompting the guards to return fire in shootings that killed or wounded the civilians.
"We will never know the extent to which Iraqi national police scrubbed the scene" of evidence that Blackwater guards were fired on, said Brian Heberlig, who is representing Slough.
One of the witnesses in the trial, Blackwater team leader Jimmy Watson, testified that on that day in Nisoor Square, he heard the incoming "pop" of what sounded like AK-47 rounds shortly before Slatten fired his weapon twice at the start of the violence.
Watson's testimony supports the idea that there was incoming gunfire because AK-47s were the type of weapons used by insurgents.
On Wednesday, Asuncion discounted Watson's testimony, saying that Watson had never said anything about incoming gunfire before.