Police are investigating the possible connection between a shooting in North Philly that injured three people and a hit-and-run where an off-duty officer was struck Sunday morning.

A violent Fourth of July weekend in Philadelphia ends with a mass shooting—three deaths and multiple injuries reported.

The shooting happened after other shootings in the city and elsewhere around the U.S. over the Fourth of July weekend. Those included at least eight people struck by gunfire near a South Philadelphia nightclub.