Guatemala's ex-police chief Erwin Sperisen has been sentenced to life in prison in Switzerland over the deaths of seven prisoners in 2006.
He was found guilty of involvement in extra-judicial killings committed during a police raid on the El Pavon prison outside Guatemala City.
The 43-year-old was tried in Geneva. He could not be extradited as he is a Swiss-Guatemalan dual national.
His arrest in 2012 followed UN efforts to crack down on impunity in Guatemala.
The court found Sperisen had been involved in the deaths of seven inmates who were shot dead after security forces stormed the El Pavon prison and took back control from criminal gangs.
It said he was "jointly responsible" for six murders and was "directly responsible" for one.
The former police chief has denied the charges.
One of his lawyers said the ruling was "shocking" and announced that his client would appeal, AFP news agency reports.
Sperisen was acquitted in Geneva of charges relating to the deaths of three escaped prisoners in 2005.
Appointed Guatemala police chief in 2004, he fled to Switzerland in 2007. As well as Guatemalan citizenship, he holds a Swiss passport, as his grandfather had emigrated from there to Guatemala.
Sperisen was tried under a law allowing Swiss nationals to be tried in their own country for crimes committed abroad.
Corruption, violence and organised crime are rife in Guatemala.
The country also has a long history of impunity, with few cases either coming to trial or resulting in convictions.
Sperisen was detained in 2012, two years after Guatemala issued arrest orders over the killings at the El Pavon prison.
The orders followed an investigation by the UN-backed international commission against impunity in Guatemala.
The former Guatemalan Interior Minister Carlos Vielmann, who fled the country at the same time as Sperisen, is due to stand trial on similar charges in Spain.