The Philadelphia Police Department has launched a new unit dedicated to investigating nonfatal shootings — a major structural shake-up amid a gun violence crisis that has left people injured or killed in record numbers. And the caseload for investigators will be huge — more than 1,800 people were shot and survived last year alone, meaning each detective could be assigned more than 40 shootings each year. John Walker, commanding officer of the new unit, said detectives working shootings citywide and coordinating more closely with homicide investigators will improve case outcomes over time.