Inside New York's anti-terror centre

One of the brothers suspected of carrying out the Boston bombings was in possession of right wing American literature in the run up to the attack, the BBC has learnt.

Tamerlan Tsarnaev, the eldest brother, subscribed to publications containing articles about government conspiracy theories and white supremacy. He also had reading material on mass killings.

The discovery that he was reading right wing material before the attack challenges the perception of the brothers as straightforward radical jihadists.

Their attack in April was one of several plots nationwide to have slipped through the net since 9/11.

In a secret location in lower Manhattan, Panorama reporter Hilary Andersson was given a glimpse of the control centre where New York's Police is stepping it up its anti-terrorism operations.

Panorama - The Brothers who Bombed Boston, Monday 5 August, 8.30pm, BBC1