Federal investigators have reportedly collected evidence with genetic samples from the home of the in-laws of one of the suspected Boston Marathon bombers.
FBI agents spent Monday visiting the Rhode Island home of the parents of Katherine Russell, the widow of 26-year-old Tamerlan Tsarnaev. Investigators have allegedly found female genetic information, DNA, on a fragment of at least one of the bombs used in the April 15 attacks.
Russell has been living at her parents's home with her young daughter since her husband was killed in a shootout with police three days after the bombings. Her attorney says she is cooperating fully with the investigation.
In a related development, a federal judge has appointed a prominent criminal defense attorney to help defend the other suspect, 19-year-old Dzhokar Tsarnaev, Tamerlan's brother.
California-based Judy Clarke has represented clients in similar high-profile federal cases involving the death penalty, including Jared Loughner, the man who severely wounded former U.S. Rep. Gabrielle Giffords and killed six others during a shooting spree in Tuscon, Arizona. Clarke negotiated a plea agreement that gave Loughner a life sentence instead of execution.
Clarke has also defended such clients as Ted Kaczynski, the so-called "Unabomber," and Atlanta Olympics bomber Eric Rudolph. Both men are also serving life sentences in prison.
Meanwhile, the lawyer representing the family of a man linked to the Tsarnaev brothers says his client is cooperating with investigators.
Attorney Richard Nicholson spoke to reporters Monday outside a home in Rhode Island, south of Boston that belongs to the family of Mikhail Allakhverdov, who has been identified in many news reports as "Misha."
Relatives have accused Misha of radicalizing Tamerlan Tsarnaev, the older of the two brothers. But U.S. media reports say no evidence has been found that Allakhverdov had any connection to the Boston Marathon bombing.
Some information for this report was provided by AP and Reuters.