'Is this some kind of fantasist?' Behind the viral BBC video

In the moments after an assassination attempt on Donald Trump's life, BBC Senior North America Correspondent Gary O'Donoghue spoke to an eyewitness who claimed he had seen a gunman on a roof.

The interview went viral, mostly because what the man had seen was so significant - but in part because he was such a compelling character.

Talking to the BBC's Media Show, O'Donoghue shares a behind-the-scenes account of the interview. He reveals his initial disbelief and his process of verifying the eyewitness' story.