About 250 students and staff were evacuated, according to officials. The school postponed all homework and in-class assignments scheduled for the next day. In a press release, the Palo Alto Police Department said it was investigating the incident, and officers described the suspect as an “unknown adult male.”

Palo Alto police were not aware at the time of the threat to JCHS, Lt. Brian Philip said. Officers have been in touch with FBI agents, who will continue the investigation and determine if the incidents are linked, Philip said.

“It is not uncommon that there’s several threats made to similar institutions,” he said.

“We would like to thank the Palo Alto police for their immediate and thorough response and to our parent body for their calm during what was understandably an upsetting experience,” Pellant said in the statement to the school community. “Our faculty and students responded in an exemplary fashion. They have every reason to be proud of themselves.”

At 3:14 p.m., San Francisco police officers said they responded to JCHS, a day school with a student body of just under 200, after receiving a call about an unknown suspect “threatening violence against the school,” SFPD spokesperson Adam Lobsinger told J. in an email.

SFPD searched the school and the surrounding area before referring the incident to its investigations unit.

Brinner, the security representative, told J. that law enforcement experts are noting an upward trend of threats either phoned in, emailed or posted online to institutions of various stripes over the past few years.

“There’s been a broader wave of calls against schools, and last year JCCs,” Brinner said, a wave that included an emailed threat to the JCC San Francisco in May, prompting an evacuation. In 2020, the S.F. center was one of more than 50 JCCs to receive bomb threats officials characterized as “vague.”

In addition to contacting law enforcement in the event of a threat, Brinner also recommended that Jewish institutions notify Jewish community security experts, either with the national Secure Community Network or the Federation’s security team at security@sfjcf.org. The Federation can help facilitate security trainings and provide other resources to local institutions.