Dallas killer Micah Johnson 'disappointed' by military

The gunman who killed five police officers in Dallas was "disappointed" by his experience in the US military, his mother has said.

Micah Johnson's mother Delphine said "the military was not what Micah thought it would be".

Former army reservist Johnson opened fire at a protest being held over the deaths of black Americans at the hands of police. He was himself killed.

The BBC's David Willis reports.