BAGHDAD — Shortly after a court in Washington reopened manslaughter cases against four American military contractors in the killings of 17 Iraqis here in September 2007, Bera’a Sadoon stood in the square where the episode occurred, nervously shaking as he tried to make sense of the case.

“Why did the case stop and now it’s coming back?” Mr. Sadoon asked Saturday, recalling the shooting in Nisour Square. The contractors, who worked as guards for Blackwater Worldwide, are accused of firing wildly from their convoy. They said they had been responding to gunfire from insurgents.

Mr. Sadoon sustained two bullet wounds in the shooting and was hit with 60 pieces of shrapnel, many of which are still in his body.

“To be honest, I think the case will be dismissed again,” he said.

Mr. Sadoon’s confusion and pessimism about the case were echoed by many other victims who did not understand the decision on Friday to resurrect the charges that were thrown out in December 2009.