Kefelgn Alemu Worku (kah-FEH'-lun ah-LEE'-moo WER'-koo) was convicted in October of identity theft and lying on immigration forms by denying he committed political violence.
Witnesses testified at his trial about torture and beatings they suffered at the hands of Worku at a prison in the 1970s during a government suppression campaign known as the Red Terror.
A former prisoner recognized him in Denver in 2011 and told authorities.
Worku has not been charged in Denver with crimes related to the prison abuse. But he could be deported to Ethiopia, where a court has sentenced him to death.
Worku has acknowledged using a false name but denied the torture allegations.