"Justice demands nothing less," according to a sentencing statement filed in U.S. District Court in Denver.
Federal sentencing guidelines for Alemu Worku's immigration violations recommend a sentencing range of zero to 18 months, but the law allows up to 10 years for each of two counts on which he was convicted, and two more years for a third.
It is unclear if upon release from prison Alemu Worku could be deported to his own country, where he has been sentenced to death, according to the sentencing statement filed by prosecutors.
Alemu Worku was convicted of immigration fraud last month after a five-day trial in which victims of Ethiopia's Red Terror testified that he was a brutal guard at the Higher 15 prison during the late 1970s. He was convicted of assuming another man's identity and lying about his background.
"While former Higher 15 prisoners in the United States continue to live every day with the physical aches and pains of their injuries and mental anguish resulting from their torture at the hands of or pursuant to the orders of the defendant, the defendant lived comfortably, safely, and free of any adverse consequences resulting from his commission of politically-motivated torture and murder during the eight years prior to his arrest in the United States and for unknown years in Kenya," according to the document.
According to the sentencing statement, an Ethiopian Federal High Court convicted Alemu Worku in absentia of genocide on Nov. 13, 2000.
At the time, Alemu Worku, who had been a member of the ruling Marxist Derg junta before it was overthrown, was apparently living as a refugee in Kenya.
After finding that he "unjustly killed 101 ... innocent individuals and inflicted injury through torture," the court sentenced him to death, according to the statement.
On release from an American prison, the Department of Homeland Security would likely pursue his removal to Ethiopia.
But the deportation of Alemu Worku, who is in his mid to late 60s, poses challenges, and could require lengthy adjudication, the document said.
If Ethiopia refused to take him, or he was granted protection under the international Convention Against Torture, it isn't clear where he could be sent, according to the document.
"The duration of litigation in a removal case can range from months to several years. It is premature to determine now whether the defendant would be subject to detention during any removal proceedings."
Though he faces a death sentence in his homeland, the last known execution in Ethiopia was in 2007. "Conditions in Ethiopia at the current time do not suggest that a death sentence would be carried out," according to the document.
In fact, the document said, "there is no record of Ethiopia having carried out any executions of former Derg members ... a number of Derg members were pardoned entirely and released."