Motive for Orlando massacre investigated as ex-wife details radical's mental illness issues

Federal investigators are examining possible motives for the massacre of 49 people in a Florida nightclub - the worst mass shooting in modern US history.

The White House and the FBI said 29-year-old gunman Omar Mateen, an American-born Muslim, appeared to be a "homegrown extremist" who had touted support not just for Islamic State (IS) but other radical groups that are its enemies.