The fact that the target was an event of great significance to Boston but not particularly significant to the wider world could indicate that the bomber was a local or at least a native of the United States. The explosions occurred on April 15, tax day, which could be a further indication of a domestic connection.
But the bombs were not directed against a government building or institution, which is often a hallmark of disaffected, lone-wolf domestic terrorists, noted some terrorism analysts. And the style of the attack, in which one explosion was closely followed by another, mimics that used by numerous groups in the
Middle East.
One government official
told the Los Angeles Times that his guess would be “self-radicalized Islamic extremists from the area.”