U.S. District Judge Cecilia M. Altonaga imposed the sentence on Charles McArthur Emmanuel, 31, who headed an elite paramilitary unit in the West African country that routinely tortured and killed people viewed as rebels or opponents during his father's presidency.
"It is hard to conceive of any more serious offenses against the dignity and the lives of human beings," Altonaga said just before announcing the sentence. "The international community condemns torture."
Emmanuel, a U.S. citizen also known as Charles "Chuckie" Taylor Jr., was convicted in October in the first use of a 1994 law permitting prosecution in the U.S. for torture committed in foreign countries. Prosecutors had asked for a 147-year sentence to send a strong worldwide message against torture, while the defense asked for 20 years.
"Many are watching this case," Assistant U.S. Attorney Karen Rochlin told the judge. "Consider the potential victims of the future."
Emmanuel showed no emotion or reaction at the sentence, but told Altonaga he will swiftly appeal. Emmanuel also said he rejected an offer from prosecutors to plead guilty in exchange for a lighter sentence.
"My innocence was important to me then, as it is now," said Emmanuel, who also offered an apology of sorts to several of his victims at the hearing. "My sympathies go out to all the people who suffered in the conflicts in Liberia and Sierra Leone.
Emmanuel's father Charles Taylor, a notorious warlord who left power in 2003 under U.S. pressure, is on trial before a United Nations tribunal in The Hague, Netherlands, for crimes allegedly committed during the Sierra Leone civil war.
Victims testified that Emmanuel, as chief of Taylor's Antiterrorist Unit, either personally tortured them or directed others to do so. People were shocked by electric devices, stabbed with bayonets, burned with cigarettes, scalding water and molten plastic, bitten by shovelfuls of ants and imprisoned in water-filled holes topped by iron bars and barbed wire.
Emmanuel personally shot several men to death at a bridge checkpoint and ordered one man beheaded with a large knife, witnesses said.
One victim, Mulbah Kamara, leaned on a metal crutch as he described his continuing pain and nightmares from the beatings and abuse he withstood.
"I am going through a lot of trauma," Kamara said. "I'm happy that I'm here, alive."
Added victim Rufus Kpadeh: "Bravo to the United States government."
The sentence marks the culmination of a U.S. Immigration and Customs Enforcement investigation that began in 2002 with a single agent looking into illegal arms exports to wartorn western Africa. Emmanuel was initially arrested in Miami for a passport violation in 2006, then indicted on torture, firearms and conspiracy charges.
The investigation spanned seven countries, involved some 200 interviews and included the delicate task of persuading frightened Liberian torture victims to travel to Miami - some staying in a hotel for the first time - to testify against a man whose unit was known as the "Demon Forces," said John Torres, acting ICE assistant secretary.
Torres said the Emmanuel case will have immense value for "the deterrence for others who think they can come to the U.S. for safe haven. This case has raised awareness internationally that this is the type of investigation ICE will pursue. It has opened up so many doors."
Emmanuel attorney Miguel Caridad argued that his client - who arrived in Africa at age 17, after a series of crimes as a juvenile in Orlando - may have thought such atrocities were "standard operating procedure" in violent western Africa and that he was vulnerable to pressure from his powerful father.
"The defendant's life has been destroyed by a perfect storm of circumstances not of his own making," Caridad said.
But prosecutor Caroline Heck Miller rejected that.
"The defendant argues that he should be excused because numerous other individuals have gotten away with torture, and because he was unfortunate in his parental origins, but he never accepts responsibility," she said.