A federal judge has sentenced former Blackwater security guard Nicholas Slatten to life in prison for his role in a 2007 shooting that killed 14 Iraqi civilians and wounded 17 others. Three other guards - Paul Slough, Evan Liberty and Dustin Heard - were each sentenced to 30 years and one day in prison for charges that included manslaughter, attempted manslaughter and using firearms while committing a felony. U.S. District Judge Royce Lamberth announced the sentences after a day-long hearing at which defense lawyers had argued for leniency, and prosecutors asked that those sentences - the minimums mandatory under the law - be made even harsher. Scroll down for video . FILE - In these various file photos, Blackwater guards, from left, Dustin Heard, Paul Slough, Evan Liberty and Nicholas Slatten. A years-long legal fight over a deadly mass shooting of civilians in an Iraq war zone reaches its reckoning point, when four former Blackwater security guards are sentenced for the rampage. Three of the guards, Dustin Heard, Evan Liberty and Paul Slough, face mandatory decades-long sentences because of firearms convictions. A fourth, Nicholas Slatten, faces a penalty of life in prison after being found guilty of first-degree murder. (AP Photo/File) Sentencing: Former Blackwater guard Nicholas Slatten (bottom right) was convicted of first degree murder and on Monday be sentenced to life in prison for his role in the 2007 Nisour Square slaughter that left 14 dead and dozens more maimed and injured. Dustin Heard, Paul Slough and Evan Liberty (clockwise from top left) were received the 30-year minimum sentences plus one day for their multiple manslaughter convictions . U.S. District Judge Royce Lamberth on Monday rejected a defense motion to impose lesser sentences on the four, as well as a motion by prosecutors to increase the penalties. Lamberth deferred formally imposing the sentences while hearing arguments from both sides on the sentencing. Defense lawyers argued for mercy but prosecutors said the men have never shown remorse or accepted responsibility. All four were convicted in October for their involvement in the killings that caused an international uproar in Nisoor Square, a crowded traffic circle in downtown Baghdad. The legal fight over the killings has spanned years. Prosecutors have described the shooting as an unprovoked ambush of civilians, though defense lawyers countered that the men were targeted with gunfire, and shot back in self-defense. Dozens of Iraqi witnesses to the bloody September day in Baghdad volunteered to travel to Washington to testify against the former guards, the New York Times reported. They described to jurors a scene of absolute horror, one that came as if out of the clear blue. They said they took cover after hearing machine-gun fire start ring after four American armored vehicles rolled into busy Nisour Square. A traffic officer who was on the scene described watching a woman cradle her dead son in her arms before she, too, was murdered by Blackwater guards. Mandatory minimums: A man caring a poster that reads 'approximate locations of victims around Nisoor Square' enters the E. Barrett Prettyman Federal Courthouse in Washington on Monday. U.S. District Judge Royce Lamberth on Monday rejected a defense motion to impose sentences lesser than mandatory minimums on the four . Family members, friends and supporters of four former Blackwater security guards arrive at E. Barrett Prettyman federal courthouse in Washington . Former co-workers: Former Blackwater security guards stand in line to enter the E. Barrett Prettyman federal courthouse in Washington in support of the men awaiting sentencing . ‘There was a lady. She was screaming and weeping about her son and asking for help,’ Sarhan Deab Abdul Moniem said through an interpreter. ‘I asked her to open up the door so I could help her. But she was paying attention only to her son.’ Majed Salman Abdel Kareem al-Gharbawi, 55, described being shot in the gut and slumping to the ground alongside another wounded man. ‘He was screaming and praying to god, for Allah to save him from this calamity,’ Gharbawi testified. ‘So I told him, let’s do that together.’ Gharbawi stayed down as the other man decided to make a run for it—a decision that cost the man his life. ‘His body was shaking violently as the bullets were piercing him and hitting the sidewalk,’ Gharbawi said. According to the Times, the Blackwater guards continued shooting into the man’s body well after he was clearly dead. The defense argued for mercy Monday by saying that decades-long sentences would be unconstitutionally harsh punishments for men who operated in a stressful, war-torn environment, and who have proud military careers and close family ties. The firearms convictions alone carry mandatory minimum sentences of 30 years in prison. The government sought sentences far beyond that, partly because it said the men have never shown remorse or accepted responsibility. Bloodbath: an Iraqi woman peeps inside the blood stained car of two women allegedly shot dead by private security guards in central Baghdad. Dozens of Iraqi witnesses would later volunteer to testify about the atrocities they saw that day . Murdered: A picture shows the blood stained and bullet riddled car of two women allegedly shot dead by Blackwater guards. One witness would later describe watching a woman cradle her dead, bullet-riddled son before she was murdered at his side . Unimaginable: Hair is seen on the bullet riddled and blood stained windshield of a car of two women shot dead. One witness said he watched a man bolt for his life only to be riddled with bullets before guards continued to fire at his clearly dead body . The sentencing is unlikely to bring an end to the legal wrangling, which began even before the guards were first charged in 2008. A judge later dismissed the case before trial, but a federal appeals court revived it and the guards were indicted again in October 2013. Even before the trial began, defense lawyers had identified multiple issues as likely forming the basis of an appeal, including whether there was proper legal jurisdiction to charge them in the first place. The statute under which they were charged, the Military Extraterritorial Jurisdiction Act, covers the overseas crimes of Defense Department civilian employees, military contractors and others who are supporting the American war mission. But defense lawyers note that the Blackwater defendants worked as State Department contractors and were in Iraq to provide diplomatic, not military, services. The legal fighting continued in the days leading up to sentencing, too, with defense lawyers seeking Friday to postpone the hearing after receiving new information — a victim impact statement from a trial witness — that they said was favorable to the defense. But Lamberth denied the request, saying there was no need to delay the sentencing. Wartorn: The defense argued for mercy Monday by saying that decades-long sentences would be unconstitutionally harsh punishments for men who operated in a stressful, war-torn environment . Self defense? Guards say they first fired under the belief that a car heading toward their convoy was rigged with a bomb .
A judge has sentenced former Blackwater guard Nicholas Slatten to life in prison for his role in a 2007 shooting that killed 14 and wounded 17 .
Charges against Paul Slough, Evan Liberty and Dustin Heard included dozens of counts of manslaughter and attempted manslaughter .
The former Blackwater guards were convicted in October on a combined 33 counts including manslaughter, attempted manslaughter and murder .
They left behind a hellish scene in a Baghdad traffic circle where bombed out and bloodied cars littered a street strewn with bodies .