An 18-year-old gunman opened fire at a library in Chico, northern California, killing two people and injuring a child before being arrested within minutes.

Police said the suspect, identified as Bradley Scott Sayer, appeared to be inspired by the Columbine school shooting and had posted related references on social media.

Authorities say he carried a shotgun, wore a shirt referencing “natural selection,” and targeted a crowded public space after scouting the building.

The victims were identified as a 74-year-old man and a 46-year-old man, while the injured child has been released from hospital, The Guardian has reported.

The suspect is expected to face first-degree murder charges as investigators examine how he obtained the weapons and his motives.