The suspect in a fatal shooting at a Northern California library on Monday was influenced by the 1999 Columbine High School massacre and other mass shootings, authorities said Tuesday.
Bradley Scott Sayer, 18, allegedly entered the Chico branch of the Butte County Library, conducted a walkthrough, then retrieved a shotgun from his vehicle before opening fire, according to the Chico Police Department. He killed two men, identified as 46-year-old Jacob Hull and 74-year-old Robert Johnson. An underage girl was also injured and treated at a hospital.
Police responded within minutes of the first 911 call, Chief Billy Aldridge said, a rapid response that he believes prevented further loss of life. Sayer was taken into custody outside the building.
Authorities stated Sayer had no known connection to the library or the victims. He had recently graduated from Chico High School on June 5, according to the FBI's Sacramento office.
During his arrest, Sayer was wearing a white T-shirt with the words "natural selection" printed on it, a phrase similar to one worn by Eric Harris, one of the perpetrators of the Columbine shooting, said FBI Special Agent in Charge Sid Patel. Butte County District Attorney Michael Ramsey added that Sayer had been a long-time follower of the Columbine shootings on social media.
Two additional firearms were discovered in Sayer's vehicle, which was parked in the library lot. Investigators are examining how he obtained the weapons. Sayer is scheduled for arraignment on Thursday.