Four security contractors convicted of killing 14 unarmed Iraqi civilians and injuring 17 others at a busy Baghdad traffic circle in 2007 were sentenced Monday to decades behind bars.

Three of the former employees of Blackwater Worldwide, Paul Slough, Evan Liberty and Dustin Heard, received a mandatory 30 years in prison for using automatic weapons to commit a felony, plus one day for underlying manslaughter and attempted manslaughter convictions.

The other, Nicholas Slatten, received a life sentence for murder. He was found to have fired the first shot, killing an Iraqi medical student driving with his mother, a dermatologist. Their car caught fire, and a grisly photograph of their charred remains was shown in court.

Slatten denied firing the shot, blaming instead government witness Jeremy Ridgeway, who pleaded guilty to manslaughter, for which he awaits sentencing.

“Give me justice,” a defiant Slatten demanded of U.S. District Judge Royce Lamberth in a packed courtroom in the nation’s capital, suggesting the verdict be set aside.

Lamberth opted instead for a life sentence.

“I fully support the jury’s verdict,” he said. “Good luck to you, Mr. Slatten.”

All four defendants, confined since being found guilty in October, appeared pale and wore beards, blue jumpsuits and shackles. They were supported by scores of family members and friends, some of whom wore shirts displaying messages championing Blackwater or urging the men's freedom.

Three siblings of a 9-year-old killed during the gunfire wore T-shirts in memory of their brother, Ali Kinani, who was killed in a car near the intersection.

Ali’s father, Mohammed, who has since moved his family to the U.S., spoke forcefully against Blackwater. He said he was pleased when the U.S. invaded Iraq in 2003 and distributed cake to celebrate. His young son, he said, would eagerly approach U.S. troops and posed for pictures despite the scorn of neighbors.

“President George W. Bush, he promised to make my country free, but Blackwater broke his mission,” he said. “A lot of American soldiers died for what Blackwater did.”

Kinani recalled unpleasant interactions he said he had with company representatives and said the security firm “is like the house of Saddam Hussein ... they say whatever they want, kill whoever” and that the U.S. government gave the company too long a leash.

Blackwater officials did not immediately comment on the sentencing.

In an emotional speech, Kinani’s wife tearfully and repeatedly asked the defendants why they killed her son.

The man accused of doing so, Slough, said before sentencing, “I could not and did not kill your son.” He said black-tipped bullets used by another contractor and not by him were responsible. Slough said the mandatory sentence he faced was “a perversion of justice.”

Other defendants pushed back on the government’s claims and their guilty verdicts, and defense attorneys took turns pointing out the difficulty of making accurate judgments in a war zone. Heard said he felt he didn’t do anything wrong. Liberty said, “I shot at two people dressed in Iraqi police uniforms and they were shooting at me – that’s the truth.”

Government prosecutors, however, pointed out no witnesses could confirm the contractors had actually been fired upon. One of their vehicles was disabled because the team, assigned to protect State Department personnel and en route to retrieve one, had fired grenades too close to themselves, Assistant U.S. Attorney Patrick Martin said during a lengthy victim-by-victim description of the 10- or 15-minute shooting spree.

“Despite their protestations,” Lamberth concluded, “it’s clear these fine young men just panicked, [and] the overall wild thing that went on here can never be condoned by a court.”

Lamberth commended the government for its investigation and the unusual prosecution. Earlier in the hearing, he rejected a defense argument that 30-year mandatory sentences violate the Constitution’s Eighth Amendment, which bars cruel and unusual punishment, citing the seriousness of the crimes.

Lamberth also denied a government motion for a higher sentencing range, made in part on the claim the massacre of unarmed civilians and resulting outrage had harmed U.S. national security.

Rather than permanently harm U.S. interests, he said, “this is probably a blip on the radar screen.”