Family of police shooting victim were seeking help for mental health crisis

Hundreds of demonstrators marched in West Philadelphia over the death of Walter Wallace (Matt Slocum/AP)

The family of a black man killed by Philadelphia police officers in a shooting had called an ambulance for help with a mental health crisis, their lawyer said.

Police said Walter Wallace Junior, 27, was wielding a knife and ignored orders to drop the weapon before officers fired shots on Monday afternoon.