Tamerlan Aguzarov, chief justice of the North Ossetian Supreme Court in Vladikavkaz, sentenced Nurpashi Kulayev to death but said the sentence would be commuted to life in prison because of Russia's moratorium on capital punishment.
Kulayev admitted participating in the 2004 raid that left 331 people dead -- more than half children -- but denied killing anybody.
The judge said 16 hostages executed by militants on the first day of the assault had died in part due to Kulayev's actions.
Aneta Gadiyeva, the mother of a victim, told reporters outside the courthouse that Kulayev should be executed because death would deprive him of those little joys he could still have during life imprisonment."
Many survivors and their relatives accuse authorities of botching the rescue operation and said victims had died as a result of gunfire by troops.
(Reuters, AFP, AP)