What are supervised injection sites, and why are they an issue in Pennsylvania’s U.S. Senate race?
Advocates say the sites can keep alive people who aren't ready for treatment. Opponents think they're still a bad idea.
Mehmet Oz is handed paper by Jessica Ohm for an autograph during his visit last month to McPherson Square Park in Kensington.Read moreAlejandro A. Alvarez / Staff Photographer
