US Russia do not have a bilateral Extradition Treaty

Russia – Republic of Dagestan (Makhachkala)

www.thebesttravelled.com 

Russia and the U.S. have no extradition deal and Russian citizens convicted by U.S. court serve their sentences in the United States.

source http://en.rian.ru/russia/20120210/171243300.html

Both parents of  Boston bombing suspects Zubeidat Tsarnaeva and her ex husband Anzor live in Makhachakala, Dagestan Capital and port city. Locate on western shore of Caspian sea, fort Maghach or Makhachala is home to the Russsia's largest mosque 'Makhachakala Grand Mosque"