The first defendant in the Crocus City concert hall attack case, Dalerdzhon Mirzoyev, has pleaded guilty on all counts, the press service of Moscow City Court told state media RIA Novosti.
He will be held in preventive custody at least through May 22.
Mirzoyev is one of two defendants implicated in the attack who are facing possible life imprisonment, as reported by state media.
The suspects — Mirzoyev and Saidakrami Rachabalizoda — appeared in a Moscow court on Sunday on charges related to the attack.
Both individuals are accused of committing a terrorist act and could be sentenced to life imprisonment, according to state media outlet RIA Novosti. The prosecution has requested detention as a precautionary measure for both defendants.
Authorities have petitioned the court to conduct Mirzoyev's hearing behind closed doors to safeguard the integrity of the proceedings, state media news agency TASS reported.