YEREVAN, Armenia -- An Armenian court on Tuesday sentenced a Russian soldier to life in prison for killing a family of seven outside a Russian military base in Armenia, which sparked a major crisis in relations between the two historic allies.

The court, at the Russian base in the Armenian city of Gyumri, found Valery Permyakov guilty of killing the family after he left his base with a machine-gun and went on a shooting rampage at their home, killing all of them including a 6-month-old infant.

Russia is Armenia's main sponsor and ally and has troops stationed there. The brutal killing sparked protests in the otherwise Russia-friendly Armenia as residents feared the supposed killer would be sent home.

Permyakov was reported to have confessed to the killing earlier in the trial but refused to give testimony. Two sets of tests by Russian and Armenian psychiatrists certified that the soldier is sane.

The family's lawyers welcomed the verdict, but insisted that the trial left many questions unanswered.

Artur Sakunts, who represents the family's relatives, on Tuesday blamed investigators for failing to establish a motive and whether Permyakov had any accomplices.

It wasn't immediately clear whether Permyakov will be serving his sentence in Armenia or be sent to Russia. Some Armenians fear that his sentence could be commuted once he's back home.