St. Stephen police are investigating a shooting this morning in which a 15-year-old was wounded three times and another teen was grazed in the head.

Police were called a Citgo station on Byrnes Drive around 4:30 a.m. after the 15-year-old showed up there with bullet wounds to the hand, arm and back, Police Chief John Waters said.

Authorities then received a call about another shooting victim at 104 Nings Place, Waters said. There, they found 18-year-old Jordan Johnson of Eutawville. A bullet appeared to have grazed his forehead, he said.

Investigators are still trying to determine what led up to the shooting, Waters said.

The 15-year-old told police he didn’t know why he was shot, Waters said. Johnson indicated there had been some sort of altercation, but he wouldn’t say what it was about, he said.

Johnson told police he shot at the 15-year-old in self-defense after the younger teen fired at him first, Waters said. Police have not verified that account, and investigators are charging Johnson with attempted murder, he said.

The 15-year-old, who is from St. Stephen, could face charges as well, Waters said.

Waters said he is still awaiting information on the identity of the 15-year-old, who is being treated at Medical University Hospital in Charleston for wounds that do not appear to be life-threatening.

Check back with postandcourier.com for updates on this developing story.