It found Hoang Ngoc Kien, 57, guilty of "murder."
In 1987, Kien had gone to Russia to work in a factory. In 1997, he met Russian woman Gerasimova Inna Andeevna, and the two lived together.
Once in 2004 the couple entertained some friends at home. After dinner, a guest named Sergei Mikhailovich Kardanov, 61, got into a minor argument with Inna and kicked her, causing her to fall. Kien intervened to protect her and the two men got into a fight.
Kien frantically waved a knife at Kardanov, and stabbed him.
Kien returned to Vietnam soon afterward, but only reported the killing to the police in 2018.