A man who sent more than 40 threatening letters to Jewish institutions was sentenced to three years in prison

A Maryland man who sent dozens of threatening letters to Jewish institutions across the country — including the Weitzman National Museum of American Jewish History in Center City — was sentenced Monday to more than three years in federal prison.

Clift A. Seferlis, 55, of Kensington, Md., apologized for his actions during a sentencing hearing in Philadelphia’s federal courthouse, saying he’d written the letters because he’d become consumed by a sense of moral outrage over the suffering of Palestinians amid the war in Gaza.

He said he never intended to act on his threats and was not a violent person, but that he understood his letters “dragged innocent people into my darkness.”

“My words are the worst of my venom, and they are awful and inflicted pain,” he said. “And if there was any way I could take it back, I would.”

Prosecutors said the letters did not simply express disagreement with Israel’s actions during the war. Instead, they said, Seferlis typed out and mailed letters that contained “vile, anti-Semitic” language about specific Jewish people or Judaism as a whole — at a time when antisemitism was on the rise.

In addition, they said, Seferlis included threats to harm the institutions he was corresponding with, and often made references to the Holocaust and Kristallnacht.

“This was pure hatred, pure antisemitism,” said Assistant U.S. Attorney Mark Dubnoff, who said he believed the war in Gaza was an “excuse” for Seferlis to unleash more broadly discriminatory views.

U.S. District Judge Mark Kearney said he was baffled by Seferlis’s actions. Seferlis is well-educated, the judge noted, but sought to stand up for people in Gaza by directing deliberately hateful language toward Jews.

“This is not writing letters and saying: ‘Dear synagogue, I disagree with Mr. Netanyahu,’” the Israeli prime minister, Kearney said. “This is, ‘We are going to destroy you.’”

Seferlis mailed the letters between March 2024 and June 2025, court documents said. His targets ranged from individual rabbis and synagogues — including in the Washington, D.C. area, where he lives — and the Weitzman, which sits on Philadelphia’s Independence Mall and bills itself as the only museum in the country dedicated to exploring the American Jewish experience.

Arthur Sandman, chief operating officer of the Weitzman, said in court that Seferlis expressed “blatant bloodlust” in the half-dozen letters he sent to the museum. The letters were often addressed to specific staffers, Sandman said, and created a profound sense of fear among employees that Seferlis knew who they were and might seek to act on his threats.

“We felt violated,” Sandman said. “We felt uncertain.”

Seferlis’ attorney, Margaret Grasso, said there was no clear explanation for why Seferlis lashed out the way he did. He works as a professional stone carver and tour guide, she said, and has a wide array of personal and intellectual interests.

Dozens of friends and relatives also submitted letters describing him as thoughtful, considerate, well-read, and civically engaged, and said his conduct in this case was a bizarre and perplexing aberration.

Seferlis was arrested last June and charged with crimes including mailing threatening communications and obstruction of free exercise of religious beliefs. He pleaded guilty in the fall.

Kearney said one of the ironies of the case is that by seeking to stand up for the Gazan people, whom he viewed as victims, Seferlis acted in a way that resembled the type of “bully” he sought to oppose.

“You became the avenging warrior against the wrong people,” he said.