Eduard Grigoryan who was serving a life sentence over the Armenian parliament shooting on October 27, 1999 died in the early hours of Friday, November 3.
Chief of Nubarashen correctoral facility Gor Ghlechyan confirmed the news, Forroghts.am reports.
After complaining of chest pain at night, Grigoryan was taken to the hospital shortly afterwards where his biological death was confirmed.
According to some reports, Grigoryan underwent a heart surgery two years ago.
The Armenian parliament shooting was a terrorist attack on the Armenian National Assembly in the capital Yerevan on October 27, 1999, by a group of five armed men who killed seven top officials.Those five perpetrators of the shooting (Nairi Hunanyan, his younger brother Karen Hunanyan, their uncle Vram Galstyan, Derenik Ejanyan and Grigoryan) were sentenced to life in prison in 2003.