FILE - A suspect in the deadly attack at the Crocus City Hall concert venue, is escorted by police in Moscow, Russia, Sunday, March 24, 2024. The March 22 attack on the concert venue killed over 140 people and marked a major failure of Russian security agencies. (AP Photo/Alexander Zemlianichenko, File)
FILE - Russian President Vladimir Putin lights a candle to commemorate victims of an attack on the Crocus City Hall concert venue, on the day of national mourning, in Russia, Sunday, March 24, 2024. The March 22 attack that killed over 140 people marked a major failure of Russian security agencies. (Mikhail Metzel, Sputnik, Kremlin Pool Photo via AP, File)
FILE - A Russian soldier secures an area as a massive blaze can be seen over a concert venue on the western edge of Moscow, Russia, Friday, March 22, 2024. The attack on a suburban Moscow concert hall that killed over 140 people marked a major failure of Russian security agencies. (AP Photo/Dmitry Serebryakov, File)
FILE - A massive blaze is seen over the Crocus City Hall concert venue on the western edge of Moscow, Russia, Friday, March 22, 2024. The attack on the venue that killed over 140 people marked a major failure of Russian security agencies. (Sergei Vedyashkin/Moscow News Agency via AP, File)
FILE - Police detain a man as he wanted to lay flowers to honor Russian opposition leader Alexei Navalny in St. Petersburg, Russia on Saturday, Feb. 17, 2024. Kremlin critics say Russian law enforcement agencies' focus on stifling political opposition contributed to their failure to prevent the March 22 attack on a Moscow concert hall. (AP Photo, File)
FILE - Workers carry the coffin of Russian opposition leader Alexei Navalny in Moscow, Russia, Friday, March 1, 2024. Kremlin critics say that Russia's security services focused on cracking down on opposition groups, distracting resources from monitoring terrorist threats. (AP Photo, File)
FILE - Russian soldiers secure an area at near the Crocus City Hall concert venue on the western edge of Moscow, Russia, on Saturday, March 23, 2024. The March 22 attack on the venue that killed over 140 people marked a major failure of Russian security agencies. (Alexander Avilov/Moscow News Agency via AP, File)
A woman takes a selfie on Red Square in Moscow, Russia, Thursday, March 28, 2024. The March 22 attack on a suburban Moscow concert hall that killed over 140 people marked a major failure of Russian security agencies. (AP Photo/Alexander Zemlianichenko)
FILE - LGBT activists wave their flags during a rally in Moscow, Russia, Wednesday, July 15, 2020. Russia's state watchdog for financial crimes added the LGBTQ "movement" to its list of extremist and terrorist organizations on the day of the March 22 attack on a Moscow concert hall. (AP Photo, File)
FILE - People lay flowers and light candles next to the Crocus City Hall concert venue, on the western edge of Moscow, Russia, Saturday, March 23, 2024. The March 22 attack on the venue killed over 140 people and marked a major failure of Russian security agencies. (AP Photo/Alexander Zemlianichenko, File)