A Maryland man who sent more than 40 threatening letters to Jewish institutions, including the Weitzman National Museum of American Jewish History in Philadelphia, was sentenced to three years in prison on Monday.

55-year-old Clift Seferlis of Garrett Park, Maryland, was sentenced to 37 months in prison, three years of supervised release, a $40,000 fine, and a $2,200 special assessment.

He had previously pleaded guilty to 17 counts of mailing threatening communications and eight counts of obstructing the free exercise of religious beliefs arising from threats to Jewish institutions, which were sent from March 2024 through at least June 2025.

A view of the National Museum of American Jewish History in Philadelphia.
A view of the National Museum of American Jewish History in Philadelphia. (credit: Shoot from WIthin)

“For more than a year, the defendant terrorized Jewish communities across the country, robbing his victims of their peace and security,” Assistant Attorney General Harmeet Dhillon said in a statement. “The defendant’s sentence should be a warning to all that religious-based terror will not be tolerated in this country.”

Perpetrator shows remorse

During a sentencing hearing in Philadelphia’s federal courthouse, Seferlis, who told FBI agents that he had previously given tours at the museum, expressed remorse for the letters, which included threats to destroy buildings and harm individuals over the war in Gaza.

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

In a joint statement, the Weitzman National Museum of American Jewish History and the Jewish Federation of Greater Philadelphia expressed gratitude for the sentencing, writing, “It is critically important that those who seek to intimidate Jewish institutions are identified, investigated, and held accountable.”