A mass shooting in Philadelphia's Grays Ferry neighborhood left three people dead and nine others injured early Monday morning, police say.Philadelphia Police Commissioner Kevin Bethel said the shooting occurred on the 1500 block of South 27th Street just before 1 a.

The shooting was one of several episodes of gun and knife violence in the city over the Fourth of July weekend.

CCTV footage from outside a home showed dozens of people taking cover as countless gunshots sounded in a Philadelphia neighborhood.