The sole gunman in a Southern California synagogue shooting in which a woman was killed told an investigator he adopted his hatred of Judaism 18 months before the fatal attack, according to a federal search warrant.

John T. Earnest, 19, also told a San Diego Sheriff's detective that he was inspired by Adolf Hitler and the suspected gunman in the New Zealand mosque shooting last March.

The search warrant, which as unsealed in a hate crimes case against Earnest, offered a few new details about the attack on the Chabad of Poway synagogue on the last day of the Jewish holiday of Passover, including when Earnest became drawn to anti-Semitism and hated of Islam.

San Diego police found a helmet with a video camera on it in Earnest's car when the San Diego man was arrested almost immediately after the April 27 shooting, which killed 60-year-old Lori Kaye and injured three others. He had an AR-15 rifle in the vehicle. It was previously known that Earnest said on the 8chan website that he planned to stream the attack live on Facebook. He never did.

"At that time, Earnest did not appear to be under the influence of a controlled substance but did appear to have a 'flat affect' as though he was detached or unaffected by his actions," the warrant states in recounting an interview that he gave to a San Diego police detective immediately after he was detained.

Earnest, an accomplished student and pianist, has pleaded not guilty to a 113-count federal indictment and faces charges of murder and attempted murder in state court, both of which may make him eligible for the death penalty if convicted. He also pleaded not guilty to state and federal charges of trying to burn a mosque in the nearby city of Escondido.

Those charges also include attempted arson at a mosque in nearby Escondido a month earlier.

A federal affidavit describes a deeply disturbed man filled with hatred toward Jews and Muslims, which is detailed in online writings. Earnest claimed to be inspired by the attacks on the mosques in New Zealand and a shooting at a Pittsburgh synagogue last fall.

Court documents said Earnest dialed 911 after fleeing the house of worship in his car and said: "I just shot up a synagogue." He went on to tell the dispatcher that he did it "because Jewish people are destroying the white race," according to the affidavit. He was arrested without a struggle.