SAN DIEGO – Prosecutors are seeking a sentence of life without parole or the death penalty for John T. Earnest, the 19-year-old man accused of killing a woman and wounding three others in a synagogue attack outside San Diego on Saturday.

At his first court hearing Tuesday, Earnest pleaded not guilty to a charge of murder with a special circumstance of a hate crime. He also faces three charges of attempted murder.

Sitting behind glass panes and wearing glasses, Earnest appeared to be looking straight at Judge Joseph Brannigan of San Diego County Superior Court, showing no emotion.

Brannigan said Earnest would be held without bail, calling him "an obvious and extraordinary risk to public safety.''

Authorities say Earnest burst into a Passover service at the Chabad of Poway synagogue and started shooting, killing 60-year-old Lori Gilbert Kaye and injuring Rabbi Yisroel Goldstein and two worshippers.

Leonard Trinh, hate crimes prosecutor for the district attorney's office, said a determination on whether to pursue the death penalty would be made later by DA Summer Stephan. There is currently a moratorium on capital punishment in California.

Stephan said at a news conference that hate crimes are especially heinous because they victimize all members of the religion, race or sexual orientation under attack.

Asked about the possibility of the death penalty, she said, "We consider this to be an atrocious crime for which there must be accountability.”

Stephan said Earnest is believed to have purchased the weapon legally but was unable to provide details on how or when that occurred.

He is slated to have a May 30 readiness hearing and a July 8 preliminary hearing.

Trinh provided more details about the assault, saying Earnest fired eight to 10 rounds before his AR-style rifle jammed. Trinh also said Earnest had a tactical vest, helmet and 50 bullets at the time of his arrest.

When his rifle malfunctioned, Earnest was chased away by a congregant with military experience who began yelling at him.

"It could have been such a bloodbath," said Goldstein, who sustained wounds to both his hands and lost his right index finger in the assault.

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Earnest shot Kaye twice before firing at Goldstein, according to Trinh. He said the suspect fired several additional rounds and shrapnel struck a man and his 8-year-old niece, wounding both.

When Earnest returned to his car, Trinh said, an off-duty Border Patrol Agent fired several rounds in his direction, striking the vehicle once. The incident was captured on surveillance tape.

After he fled, the defendant called 911 and told the dispatcher his location about two miles away. He was wearing the vest, and a rifle with five loaded magazines and a tactical helmet were found in the car, Trinh said.

San Diego Sheriff William Gore said Earnest posted an online “manifesto” in which he criticized Jews and also celebrated the slaying of 50 Muslims at shootings at two mosques last month in Christchurch, New Zealand. The manifesto echoes common white supremacist themes.

Earnest, a nursing student at nearby Cal State San Marcos, was an accomplished scholar, athlete and piano player whose embrace of white supremacy and anti-Semitism has dumbfounded those who thought they knew him well.

His family released a statement Monday decrying Earnest's actions, distancing themselves from the horror he had caused and expressing condolences to the people he had harmed at the synagogue in Poway, 20 miles north of San Diego.

"Like our other five children, he was raised in a family, a faith and a community that all

rejected hate and taught that love must be the motive for everything we do,'' the statement said. "How our son was attracted to such darkness is a terrifying mystery to us, though we are confident that law enforcement will uncover many details of the path that he took to this evil and despicable act."

Stephan said it's not surprising the suspect’s family may not have noticed their son radicalizing because the process often takes place in privacy online.

Earnest apparently became radicalized sometime over the last two years. Before that, he counted Jews and black people among his friends. His father, John A. Earnest, is a popular physics teacher at Mt. Carmel High School in San Diego, which his son attended.

Owen Cruise, 20, said saw he saw the younger Earnest at school every day during their senior year when they took calculus and physics together. They were also in the school’s amateur radio club.

“He was very close to his dad,” Cruise said. “He always hung out in his classroom, came to see him at lunch. He always seemed like a nice guy … He didn’t seem like the type of person who would go off the deep end.”

Contributing: The Associated Press