They spent 10 years in the U.S. during a formative period of their lives, exhibiting normal behavior for first-generation immigrants, said Mitchell Silber, a former intelligence official in the New York Police Department.

WSJ: Homegrown Terror Threat Appears to Be Rising

The brothers spent 10 years in the U.S. during a formative period of their lives, exhibiting normal behavior for first-generation immigrants, said Mitchell Silber, a former intelligence official in the New York Police Department.

WSJ: Renewed Fears About Homegrown Terror Threat