Moscow attack: who are the four suspects placed in pre-trial detention for terrorism?. The alleged attackers, who showed signs of torture when they appeared before a Russian court, face life imprisonment.
Two of them pleaded guilty, according to the court. Numerous calls to reinstate the death penalty - suspended by a moratorium since 1996 - have been launched by Russian officials. The attack, claimed by the Khorasan Islamic State terrorist group in the hours after the bombing, led to an instant manhunt by Russian authorities.