On Wednesday, Slatten was sentenced to life in federal prison for initiating a massacre that left 14 Iraqi civilians dead.

Responsible for firing the first bullet in the Nisour Square massacre in 2007, former Blackwater security contractor Nicholas Slatten was sentenced Wednesday to life in federal prison. Last year, Slatten was convicted of first-degree murder after murdering an aspiring doctor without provocation.

At approximately noon on September 16, 2007, a Blackwater convoy codenamed Raven 23 disobeyed orders from U.S. Embassy officials to remain in the Green Zone and instead established a blockade at Nisour Square in Baghdad.

While driving his mother to an appointment, Ahmed Haithem Ahmed Al Rubia’y stopped his white Kia sedan at the checkpoint and waited for the Blackwater mercenaries to let them pass. Hiding inside the convoy’s command vehicle, Slatten aimed his SR-25 sniper rifle through a gun portal and fired a round at Ahmed.

As Ahmed’s head exploded, his car slipped into neutral and slowly began to approach the Blackwater convoy. While attempting to stop the car, Iraqi police officer Ali Khalaf Salman raised his left arm signaling the shooters to stop firing. Inside the sedan, Ahmed’s mother, Mahassin Mohssen Kadhum Al-Khazali, clutched his bleeding head while screaming, “My son! My son! Help me, help me!”

A Blackwater turret gunner, Jeremy Ridgeway, opened fire killing Ahmed’s mother. Another Blackwater shooter launched an M-203 grenade that caused the sedan to erupt into flames. Unleashing sniper fire, machine guns, and grenade launchers, the Blackwater convoy murdered ten unarmed men, two women, and two boys, ages 9 and 11. At least 17 more victims were wounded. The only damage inflicted upon the convoy’s command vehicle came from shrapnel by an American grenade fired at close range by a Blackwater operative.

According to witnesses, Nicholas Slatten, Paul Slough, Evan Liberty, Dustin Heard, and Jeremy Ridgeway attempted to kill everyone inNisour Square. Another turret gunner, Matthew Murphy, waved his arms warning nearby Iraqis to get down.

After ignoring repeated orders to cease firing, the massacre finally ended when Blackwater operatives turned their guns on each other. Instead of killing their own teammates, the shooters eventually decided to stop firing. As the convoy exited the square, some of the shooters continued indiscriminately firing their machine guns at civilian vehicles.

In December 2008, Ridgeway pleaded guilty to voluntary manslaughter and attempt to commit manslaughter. As Ridgeway began cooperating with prosecutors, Judge Ricardo Urbina of Federal District Court in Washington threw out the indictments against Slatten, Liberty, Slough, Heard, and Donald Ball. An appeals court reversed his ruling in 2011, allowing prosecutors to obtain indictments against them. The prosecution chose not to indict Ball again.

On October 22, 2014, Slatten was found guilty of first-degree murder. Slough was convicted on 13 counts of voluntary manslaughter, 17 counts of attempted manslaughter, and one firearms offense. Liberty was found guilty of eight counts of voluntary manslaughter, 12 counts of attempted manslaughter, and one firearms offense. Heard was convicted on six counts of voluntary manslaughter, 11 counts of attempted manslaughter, and one firearms offense.

On August 4, 2017, a three-judge panel of the U.S. Court of Appeals for the District of Columbia Circuit tossed Slatten’s murder conviction and ordered the other defendants to be re-sentenced. In December, Slatten was found guilty of first-degree murder in the killing of Ahmed Haithem Ahmed Al Rubia’y and the other innocent people gunned down during the massacre.

The appeals court ordered Slatten’s three co-defendants – Paul Slough, Evan Liberty, and Dustin Heard – to be re-sentenced for their roles in the crime. Slough, Liberty, and Heard remain in custody and their re-sentencing proceedings are scheduled for September 5.

On Wednesday, Slatten was sentenced to life in federal prison for initiating a massacre that left 14 Iraqi civilians dead, including 10 men, two women, and two boys, ages 9 and 11. At least another 17 victims were also injured for no justifiable reason.