The search for the motivations of the alleged Boston Marathon bombers stretches from New England to Central Asia, but a lot of attention has been focused on Dagestan.
The mostly Muslim republic is located in the southernmost part of Russia, and it's been the battleground in a low-level insurgency that takes lives nearly every day.
One of the suspects, Tamerlan Tsarnaev, traveled to Dagestan twice in recent years, and investigators want to know whether that experience led him toward a radical and violent form of Islam.
Tamerlan Tsarnaev's parents and other relatives lived in the republic'