Blackwater guards, from left, Dustin Heard, Evan Liberty, Nicholas Slatten and Paul Slough were pardoned by President Trump this week. The former government contractors were convicted in a 2007 massacre in Baghdad that left more a dozen Iraqi civilians dead.

FILE – This combination made from file photo shows Blackwater guards, from left, Dustin Heard, Evan Liberty, Nicholas Slatten and Paul Slough. On Tuesday, Dec. 22, 2020, President Donald Trump pardoned 15 people, including Heard, Liberty, Slatten and Slough, the four former government contractors convicted in a 2007 massacre in Baghdad that left more a dozen Iraqi civilians dead and caused an international uproar over the use of private security guards in a war zone. (AP Photo/File)