District 1 officers responded to a Shooting on the lot of the QT located at 4101 Gravois around 10:30 p.m. on July 13.
A 19-year-old man told officers he was pumping gas on the lot when he was approached by a man, possibly in his 30s, who offered to sell drugs to the 19-year-old man.
The 19-year-old man and the other man began to argue. A security guard saw the argument and walked toward the men attempting to intervene.
The man produced a handgun, possibly a revolver, and shot the 19-year-old. The man then got into the passenger seat of a nearby vehicle which fled the lot.
The 19-year-old was struck in the arm. He was transported by EMS to an area hospital for treatment.
The investigation is ongoing.