US prosecutors had alleged that Joseph Manuel Hunter, 53, paid two men $35,000 each to kill a woman, whose body was then tossed on a pile of garbage.
“With zero regard for human life, Joseph Hunter callously helped to arrange the murder of a Filipino woman in exchange for money,” US Attorney Geoffrey S. Berman said.
The other two men, Adam Samia and Carl David Stillwell, are serving life in prison. Samia fired two shots into the woman’s face and Stillwell helped dispose of the body, prosecutors said.
The three men were convicted last year after a 12-day trial. The investigation into the three men was an international effort, bringing together US law enforcement agencies with the Royal Thai Police and the Philippines National Police.
Hunter, whose nickname is “Rambo,” provided the other men with their weapons, according to the US Department of Justice.
Hunter’s attorney, Arnold J. Levine, confirmed to CNN that Hunter’s PTSD was cited as a mitigating factor in court on Thursday. Levine declined to comment further.
‘Ringleader of trained assassins’
Hunter was in the Army from 1983 to 2004 and left the service as a sergeant first class. While in the Army he was a master drill sergeant and a sniper instructor.
Hunter, who for years worked as a soldier of fortune, is already serving a 20-year sentence over a range of charges, including the attempted murder of a US drug enforcement agent.
He was sentenced in federal court in February 2015 over the planned killing of a US Drug Enforcement Administration agent, as well as a DEA informant.
“Hunter and his cohorts turned from serving their countries as soldiers to becoming mercenaries for hire, plotting to kill a DEA agent and informant and trafficking in massive quantities of cocaine,” the attorney said.
In 2013, Hunter hired a group of four former soldiers from the US, German and Polish armed forces to act as bodyguards and hit men for what they thought were a Colombian drug cartel, according to the US Attorney’s Office.
In March 2013, Hunter described his work to one of his teams of contractors as “like a military mission,” according to the US Attorney’s Office.
“You know, you see everything. You see James Bond in the movie and you’re saying, ‘Oh, I can do that.’ Well, you’re gonna do it now,” he told the team.
In a recorded meeting, Hunter claimed he’d taken part in weapons trafficking and used grenades to carry out an attack.
CNN’s Ben Westcott, Rob Frehse and Augusta Anthony contributed to this report.