WASHINGTON - A federal judge on Thursday greatly reduced the sentences of three former Blackwater security contractors, in the latest development from a complex case dating back to the 2007 shootings of unarmed civilians in Baghdad.

U.S. District Judge Royce Lamberth sentenced Paul Slough to 15 years in prison, Evan Liberty to 14 years and Dustin Heard to 12 years and seven months. All three had received 30-year terms in a 2015 trial -- a mandatory sentence for the commission of a felony while using a military firearm. A fourth defendant in the same trial, Nicholas Slatten, was sentenced to life in prison.

The case stems from a chaotic 2007 incident when the men’s Blackwater unit opened fire at a Baghdad traffic circle, killing 14 unarmed Iraqis and wounding 17. The men all essentially blamed the fog of war, claiming they mistakenly believed they were under attack.

The shootings strained U.S.-Iraqi relations and focused intense international scrutiny on the extensive use of private military contractors in Iraq.

Those convictions were all overturned on appeal in 2017. The three-judge panel ruled that the 30-year mandatory sentence was unjust and excessive; the rule was meant to be used on drug traffickers and gang members, and had never before been applied to military contractors who had essentially be deputized by the U.S. government.

Slatten, who prosecutors contend shot first and instigated the massacre, was retried separately and was once again sentenced to life last month.