Lakeland, Florida police say Shawn Plain, 19, was charging his cell phone in an apartment building laundry room when a male appeared at the door and allegedly shot at him.
A Florida boy shot an apartment building security guard with a BB gun and was, in turn, shot dead.
Feeling stings in his face, authorities say Plain pursued the male and others and allegedly opened fire after believing he'd been shot.
Fifteen-year-old Stephen Brenor was hit in the leg while his alleged companions fled.
Plain allegedly told police he then returned to the laundry room for his cell phone before going back to the parking lot.
According to police, Brenor then told Plain he was sorry for shooting him and asked the guard to call an ambulance.
Help would arrive too late for Brenor, who died from his injuries.
The Lakeland Police statement on the incident described Brenor as a "documented associate gang member."
Plain was transported to Lakeland Regional Health and treated for two pellet wounds to his face.
The homicide investigation is ongoing at this time as detectives continue to canvass the area and interview witnesses, police said.