DENVER (AP) — A man accused of being a brutal Ethiopian prison guard during government-sponsored violence in the 1970s was sentenced Friday to 22 years in prison for immigration violations.

U.S. District Judge John Kane said the maximum sentence for Kefelgn Alemu Worku (kah-FEH’-lun ah-LEE’-moo WER’-koo) was necessary to prevent the U.S. from being known as a safe haven for violators of civil rights.

“If any case calls for a maximum punishment it seems to be this one,” Kane said.

“The relatively harmless lifestyle he has had in the United States does not change the character flaw of psychopathy.”

At Worku’s trial, witnesses testified that he participated in beatings and torture at Higher 15, a detention center established during the political violence in Ethiopia known as the Red Terror.

Human Rights organizations, including Amnesty International, have said thousands of people were killed.

Worku was convicted of assuming another man’s identity and lying on U.S. immigration forms. He has denied committing acts of political persecution.

He was spotted by chance in 2011 at an Ethiopian restaurant by a man who alerted authorities.

In rambling testimony before sentencing, Worku recalled the political turmoil in Ethiopia. Wearing beige prison scrubs, he apologized for his immigration crimes and acknowledged working in the prison but denied the abuse claims.

“If I was who they are accusing me of being — a monster — I don’t deserve to live,” Worku said in a scratchy voice, speaking through an interpreter. “I wasn’t that kind of a monster. I didn’t have that kind of authority.”

Samuel Ketema, a former prisoner who spotted Worku at the restaurant, was pleased with the sentence.

“I am happy. I am speechless,” he said.

Worku lived in Denver for eight years before Ketema recognized him and alerted law enforcement that Worku was a “big fish” at the prison and was “the most feared.”

Worku has not been charged in this country with crimes related to the violence. In Ethiopia, a high court in 2000 convicted him in absentia of genocide and sentenced him to death, U.S. prosecutors wrote in court documents.

The Ethiopian court found Worku “unjustly killed 101 . innocent individuals, and inflicted injury through torture,” the documents say.

Worku is believed to be in his 60s. Kane said he will likely be deported after he serves his sentence.

The man who spotted Worku by chance at a suburban Denver Ethiopian restaurant in 2011, was among the witnesses pleased with the sentence.

“I am happy. I am speechless,” said Samuel Ketema.

Worku has acknowledged using a false name to get into the U.S. but denied the torture allegations.

The U.S. Justice Department has used Worku’s case to encourage refugees to report human rights abusers hiding in plain sight.

The department’s Human Rights and Special Prosecutions unit says it has secured convictions against a former Guatemalan officer who hid his role in a 1982 massacre, an ex-Salvadoran colonel who lied on immigration forms about his actions during that country’s civil war, and a Bosnian man who admitted concealing his affiliation in a military brigade that committed atrocities against Muslims.

Witnesses at Worku’s immigration fraud trial spoke of being bound and beaten with cattle prods, electric wires, sticks and wood.

One woman said she was sent to the prison as a 16-year-old high school student in 1977 and interrogated about her political affiliations. She said she saw Worku shoot and kill three people, including a teenage boy, then order other prisoners to drink blood that pooled up on the floor.

Worku was a member of the communist Derg regime that came to power over the 1974 overthrow of Emperor Haile Selassie. Prosecutors say he eventually took another man’s identity and came to the United States in 2004 from Kenya, where he was living as a refugee.

Worku’s federal public defender, Matthew Golla, has questioned how witnesses could accurately identify Worku more than 30 years after the events at the Ethiopian prison.

Although Worku was sentenced to death in Ethiopia, there is no record of that country having carried out executions of other former Derg members, prosecutors wrote.