One person died and three others were injured Saturday when a gunman entered a synagogue outside of San Diego and opened fire as the Jewish community marked the last day of Passover.
The shooting occurred at the Chabad of Poway synagogue in Poway, California about 20 miles north of San Diego. Police said they responded to reports of a gunman around 11:30 a.m.
4 people hit in the shooting were admitted to the trauma unit at Palomar Medical Center at around 12:30 p.m. An older woman died on arrival. The other three patients are in stable condition.
Authorities said the gunman was a white male who was wielding an AR-style rifle. As the gunman fled the scene, an off-duty Border Patrol agent opened fire but did not hit him.
A 19-year-old man was detained for questioning in connection with the shooting. Law enforcement have identified the suspect in custody as John Earnest.
Poway Mayor Steve Vaus said members of the congregation engaged the gunman, preventing greater tragedy.
"It was a hate crime," Vaus told MSNBC.
An open letter posted on the internet under Earnest's name contained an anti-Semitic diatribe. Four law enforcement sources told NBC News that they believe the letter is authentic.
The letter praises Robert Bowers, who opened fire at the Tree of Life synagogue in Pittsburgh six months ago, killing 11 people.
Police said they were also trying to determine whether the suspect was linked to an arson at a mosque in Escondido.
The FBI is also on the scene working with local law enforcement on the investigation.
California Gov. Gavin Newsom expressed condolences to the victims and their families.
"While we continue to learn more about what transpired, we can't ignore the circumstances around this horrific incident," Newsom said. "No one should have to fear going to their place of worship, and no one should be targeted for practicing the tenets of their faith."
Rep. Scott Peters said he was praying for those affected by the shooting.
"We forcefully condemn the evil of anti-Semitism and hate," Trump said during a political rally in Wisconsin on Saturday.
The shooting comes exactly six months after a shooting at a Pittsburgh synagogue left 11 people dead.