In a news conference yesterday afternoon, Austin Police Chief Art Acevedo took to camera to describe his impression of Larry McQuilliams, the man who terrorized the city of Austin last week by going on a shooting spree in the wee hours of black Friday, armed with a .22 and an AK-47.

Previous information revealed that McQuilliams was a Ron Paul fan with conservative leanings.

“This man, by no means can you call him anything but an extremist. And if you look at what he did, he terrorized a city. He’s just an American terrorist,” said Acevedo.

Police found extremist religious ideology in the vehicle that McQuilliams rented to carry out his shooting spree and investigators found “Vigilantes of Christiandom, the story of the Phineas Priesthood” — a book best known to white supremacy groups — written by a white supremacist to condemn the “mixing of races.”

“The Phineas Priesthood is really not a group or an organization at all. It is a concept,” Mark Potok, Senior Fellow at the civil rights organization Southern Poverty Law Center, told KVUE. “Basically his idea is that if a person performs a so-called Phineas action, which is, meaning to murder people who have relationships across the races, then they are automatically a member of the Phineas Priesthood.” McQuilliams wrote in the book that he was a high priest.