Suspected California library gunman influenced by Columbine shooting and wore matching shirt, officials say

The suspected gunman who unleashed a barrage of gunfire inside a Northern California library on Monday, killing two people, was influenced by the 1999 Columbine High School shooting and other mass shootings, officials said Tuesday.

The suspect, 18-year-old Bradley Scott Sayer, had no known connection to the library or any of the victims, the Chico Police Department said.

Before opening fire, he allegedly conducted a walkthrough of the building, went to his vehicle and grabbed a shotgun. Once at the front of the Chico branch of the Butte County Library, Sayer fatally shot a man at the main door and another inside, authorities said.

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Following multiple 911 calls, officers arrived at the scene and set up a perimeter. Sayer then exited the building and was taken into police custody.

"From the first 911 call to having him in custody was less than four minutes," said Chico Police Chief Billy Aldridge, who noted that gunshots and screams could be heard on one 911 call and that the fast police response prevented the taking of more lives.

The man at the entrance was shot in the leg and head, and another man inside the building was shot in the head, police said.

The victims were identified as 46-year-old Jacob Hull and 74-year-old Robert Johnson. An underage girl was injured and treated at a hospital. In total, eight shots were fired, police said.

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Sayer had just graduated from Chico High School on June 5, said Sid Patel, the special agent in charge of the FBI’s Sacramento office.

A search of Sayer's vehicle, located in the library parking lot, uncovered two additional firearms. Investigators were looking into how he acquired the weapons.

At the time of the shooting, Sayer was wearing a white T-shirt inscribed with the words "natural selection," mimicking a T-shirt with the same slogan worn by Eric Harris, one of two shooters in the 1999 Columbine massacre in Colorado, Patel said, The Associated Press reported.

"He had been a fan, and a fan for a long time" of the Columbine shootings on social media, Butte County District Attorney Michael Ramsey said.

Sayer is scheduled to be arraigned Thursday, Ramsey said.