An analysis of DNA obtained from pieces of the detonated Boston Marathon explosives found no matches to the widow of dead suspect Tamerlan Tsarnaev or to either of the suspects, a law enforcement official said Friday.
The official, who is not authorized to comment publicly, said the source of the DNA is "unknown,'' adding that it could belong to any one of a number of people, from the point of the bomb-component's manufacture and distribution to sale.