GARLAND, Texas (AP) — Police say three teenagers were killed and a fourth was critically wounded when another teen opened fire inside a Dallas-area gas station.

Police say they arrested a 14-year-old boy who they suspect as the shooter on Monday. The shooting happened Sunday night in the Dallas suburb of Garland. Police say the shooter exited a white pickup truck, opened the door to the store and began firing inside.

The shooter then got back into the truck, which sped away. Police say four people who were shot were boys ages 14, 15, 16 and 17.

Three were pronounced dead at the scene. The fourth was taken to a hospital in critical condition.