Boston update: Female DNA found on bomb

Updated
 

Investigators have taken a DNA sample from the wife of slain suspect Tamerlan Tsarnaev. They want to compare it with the female DNA discovered on the pressure cooker from one of the Boston bombs. The FBI is also examining whether or not Tamerlan Tsarnaev met with two men in Dagestan who are considered radical Muslims, NBC News’ Pete Williams reports.

Boston update: Female DNA found on bomb

Updated