We ' re learning more about the brothers suspected of the Marathon bombing . The older of the alleged Marathon bombers , suspected Cognitive.IdentifyCategorize.Unspecified Tsarnaev , started bombing Conflict.Attack.DetonateExplode Friday prayers at the Islamic Society of Boston , in Cambridge , about a year - and - a - half ago .

The defense lawyer for suspected Boston Marathon bomber Dzhokhar Tsarnaev told the jury at suspected Cognitive.IdentifyCategorize.Unspecified trial Wednesday that he helped carry out the deadly 2013 attack , but contended that Tsarnaev ' s older brother attack Conflict.Attack.Unspecified the mastermind behind the plot .