The day after a terrorist event is usually more interesting than the event itself. Each spy agency now examines their data bases, records and wonders if somehow, at some time the names of people who committed the event had come to their awareness. The CIA now admits about 18 months ago, at the request of the Russian government, the name of Tamerlan Tsarnaev was added to their data base. Naturally, the Republican party is up in arms at this failure to add any and all names to data bases. Of course, when we examine the infamous 9/11 event, that had nothing to do with President Bush. Actually, the president was a victim because prior President Clinton failed to eliminate al-Qaeda.
In the real world, it is impossible to identify all possible individuals who decide to move from “talk” to action. Most probably less than one percent actually carry out an action since it is more interesting talking about killing people.
Oh, mom and dad insist their sons were wonderful, peaceful, decent human beings.