An FBI statement said that about five minutes before the shooting Saturday it received multiple tips through its website and phone number about an anonymous post on social media that contained threats but “did not offer specific information about the post’s author or threat location.”
The FBI said its employees acted immediately to determine the author of the posts, but the shooting took place “before the suspect could be fully identified.”
“The FBI thanks the alert citizens who saw and reported the post,” the statement said.
After the shooting, which left one woman dead and three wounded, police arrested John Earnest, 19, who is also suspected of writing a lengthy manifesto with references to white supremacy and the recent shootings at places of worship in Pittsburgh and New Zealand.
On Sunday, Earnest was booked on one charge of murder and three charges of attempted murder.
Police said he was armed with an AR-15-style firearm when he stormed into the Chabad of Poway synagogue a little before noon Saturday, yelling anti-Semitic slurs. The synagogue was more full than usual, because it was a holiday.
The congregation’s rabbi, Yisroel Goldstein, tried talking to the man after he opened fire, but he fired again. One congregant, Lori Gilbert Kaye, 60, died after jumping in front of the rabbi to protect him. The rabbi was hit in both hands.
The shooting in Poway, about 25 miles north of San Diego, coincides with a significant spike in hate crimes, including acts of anti-Semitism.
Earnest’s family released a statement Monday saying it was saddened by the attack but that “our sadness pales in comparison to the grief and anguish our son has caused for so many innocent people.”
This article originally appeared in The New York Times.