The investigation into the massacre of Nepal's royal family blamed a drunk and drugged Crown Prince Dipendra for the deaths of the king and queen and six other family members.
Prince Dipendra, aged 29, shot himself and later died. He shot all immediate members of the royal family in the royal palace, including King Birendra, 55, Queen Aiswarya, 51, and Prince Nirajan, 22.
At one stage the Nepalese authorities tried to suggest that the murders had been caused by an accidental shooting.
The slaughter at Narayanhiti Royal Palace was the worst mass murder of royals since the Romanovs were killed on Lenin's orders 1918 during the Russian revolution.
The investigation led by Supreme Court Chief Justice Keshav Prasad Upadhaya and House Speaker Taranath Ranabhat said Dipendra had consumed alcohol and smoked cigarettes laced with opium before he walked into the billiard room of the palace on the night of 1 June and gunned down the nine victims.