NEW YORK — Federal authorities believe that an explosive device found Monday in a mailbox at the home of George Soros, the billionaire philanthropist who has been a target of right-wing critics and conspiracy theorists, was left there by someone and was not delivered by the Postal Service, several law enforcement officials said Tuesday.
Soros’ home is in a suburb of New York City. The device, constructed from a length of pipe about six inches long filled with explosive powder, was “proactively detonated” by bomb squad technicians, according to one of the officials, all of whom were briefed on the investigation into the device.
The motive of the would-be bomber or bombers remained unclear, one of the officials said, adding that there had not been any claim of responsibility.
Authorities, though, had no evidence of a connection between Soros’ critics and the incident. Soros, who made his fortune in finance and is now a full-time philanthropist and political activist, is a favorite focus of the ire of right-wing groups. In recent days, some have falsely speculated that he funded a caravan of migrants moving north in Mexico.
Soros was not home when the device was discovered by a caretaker, another one of the officials said. It was rigged with a detonator, and it could have maimed or killed someone had it exploded.
A senior law enforcement official described the pipe bomb as “smaller than what we typically see.”
The investigation is being conducted by the New York offices of the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives, according to several of the officials, all of whom spoke on the condition of anonymity.
Officers from the Bedford, N.Y., Police Department initially responded to the Soros home in the hamlet of Katonah, at about 3:45 p.m. Monday in response to a call from the caretaker about a suspicious package. The Westchester County Police Department’s bomb squad was then called, as were federal and state investigators.
“The caretaker went out to collect the mail and didn’t make it back to the residence,” a senior law enforcement official said. The device was packed in an envelope that was about 8 by 10 inches and “looked suspicious.” The caretaker “dropped it in the woods on the way back to the residence.”
Another official said investigators photographed the package before detonating the device. The images have been reviewed by postal inspectors, the official said, who concluded the markings on the envelope were probably intended to make it appear as if the package was sent through the mail, though they believed it was not.
The inspectors, the official said, also interviewed the mail carrier on that route, who did not recall delivering such a package.
Two FBI Joint Terrorism Task Force squads that handle domestic terrorism cases were involved in the investigation, one of the officials said, identifying them as a unit based in the bureau’s office in nearby Rye, N.Y., and another in Manhattan that has several agents trained in investigating explosives.
Agents were canvassing the area around the Soros home for surveillance cameras in an effort to determine whether the person who left the device had been captured doing so, or approaching or leaving, one of the officials said.
Soros, who was born in Hungary, made his fortune running a hedge fund. He donates frequently to Democratic candidates and progressive causes and has given at least $18 billion to his Open Society Foundations to promote democracy and human rights around the world.
He became a major political donor in the United States during George W. Bush’s presidency. He spent millions backing John Kerry’s unsuccessful bid to deny Bush a second term, was an early backer of Barack Obama’s 2008 presidential campaign, and contributed more than $25 million to Hillary Clinton and other Democratic candidates and causes during the 2016 election cycle.
His activism has made him a villain to conservative groups and the target of anti-Semitic smears. Roseanne Barr called him a Nazi in an infamous tweetstorm.
Though Soros’ name has become a trigger for a subset of Republicans and conservatives, he has said that his main goal was to see a return to bipartisanship.
He has said it was the extremism of the Republican Party that had prompted him to become a major Democratic donor, but also said he was opposed to the extreme left.
“I don’t particularly want to be a Democrat,” he said.
Bedford is about 50 miles north of Manhattan and has been home to many well-to-do city transplants, including Martha Stewart, Glenn Close, and Ralph Lauren. Katonah, where Soros has a home, is known for its cultural offerings, including the Caramoor Center for Music and the Arts and the Katonah Museum of Art.
The town is known for its insularity and lack of gossip, which allows for well-known residents to fly under the radar. “They look to Bedford as to being protective of their privacy,” John Stockbridge, Bedford’s historian, said in a phone interview.
Stockbridge said the town has largely avoided drama or violent scares. “I’ve been here for 35 years, and I don’t remember any incident like what you’re talking about,” he said.