It happened outside the Sunrise Deli II on North 27th Street near Cambria Street around 1 a.m. Tuesday.
Police said a 29-year-old woman, the innocent bystander, was shot in the back and the chest. She was taken to the hospital in critical condition.
Investigators call the other shooting victim, a 32-year-old man, a suspect. He is in stable condition.
Police are looking for another suspect who fled the scene.