Now that one of the Boston Marathon bombing suspects is dead and the other is in custody, the next step in the investigation is finding answers.
Fox News reports that officials discovered that the older of the brother suspects, 26-year-old Tamerlan Tsarnaev, made an extended trip to Russia in 2012. It is unclear what he did on this trip and investigators wonder if he had foreign training or was directed by a foreign terrorist organization while he was there.
Tamerlan Tsarnaev was killed in a shootout with law enforcement early Friday morning after being identified as one of the suspects in the Boston Marathon bombing. The other suspect, his younger brother, 19-year-old Dzhokhar Tsarnaev, was captured hours later. The next step is to put the pieces together to figure out why these two young men did what they did.
The brothers are originally from Chechnya, but moved because of the war with Russia. So far, there is no evidence that they were acting on behalf of the Chechen cause.
Tamerlan was a self-described "very religious" Muslim. His cousin describes him as a man who was never happy or smiling.
"He used to strike his girlfriend," the cousin said. "He hurt her a few times. He was not a nice man. I don’t like to speak about him. He caused problems for my family.”
It's speculated that Tamerlan learned how to create a detonator for the bombs he used in Monday's attack while he was on the six-month trip to Russia.
As the question of whether foreign terrorist groups were involved looms, investigators will be working around the clock to find the answers that the victims of the attack deserve.