Authorities tracing the suspects' activities in the weeks before the bombing are focusing on the Tsarnaev brothers' home in Cambridge.
If, as suspected, the brothers planned the marathon bombings in that apartment, did they leave behind any evidence, and did anyone help them?
Paula Newton is OutFront tonight from Cambridge where neighbors have questions of their own.
Investigators have found female DNA on at least one of the bombs used in the Boston attacks.
What exactly does that mean?
Our Susan Candiotti has story.
Tamerlan Tsarnaev's uncle told CNN right after the bombings that a man named "Misha" is the person who quote "brainwashed" his nephew into radicalism.
Today, a U.S. government official told CNN that the FBI has interviewed a Rhode Island man named "Misha" about his links to the Tsarnaev family.
OutFront is the reporter who found and spoke to "Misha": Christian Caryl from the New York Review of Books.
As the Boston bombing investigation focuses on the Tsarnaev brothers' possible terror ties to Dagestan and neighboring Chechnya, one disturbing trend in that part of the world is the rise of women suicide bombers.
They're known as "black widows" and named that way because many are wives of insurgents killed by government forces.
Nic Robertson is in Dagestan with our OutFront investigation.
Prosecutors building their case against Dzhokhar Tsarnaev are relying on a critical piece of evidence: surveillance cameras.
While these eyes in the sky provided key intelligence that led to the suspects being identified - they're also part of a larger debate that's pitting public safety against your privacy.
Our Tom Foreman is OutFront with the story.