President Obama told mourners that the American people must insist that “there is nothing normal about innocent men and women being gunned down where they work”.

A total of 12 were killed last Monday at the Washington Navy Yard by contractor Aaron Alexis, who was himself shot dead by police.

The 34-year-old reportedly had untreated mental health difficulties.

Read more at http://www.bbc.co.uk/news/world-us-canada-24202316.