VLADIKAVKAZ, Russia — A court in southern Russia said the only attacker to survive the Beslan school siege deserves the death penalty but sentenced him to life in prison toay because Russia has a moratorium on capital punishment.

Nur-Pashi Kulayev was convicted of murder and terrorism in the September 2004 tragedy, which left 331 people dead, more than half of them children.

Most died in the climactic conclusion to the siege, when explosions tore through the school and security forces stormed the building where the 1,100 people had been held for three terrifying days.

Mothers of the victims crowded the courtroom on the eighth day of the verdict reading to hear the sentence. Many wore black and some held banners showing pictures of tanks and dead children. The banners said they would never forgive "the authorities who let Beslan happen."

Survivors and victims' relatives claim many deaths occurred because troops fired at the school from tanks and flame-throwers, sparking a fire that caused the roof to collapse over many wounded.