The FBI really did seize Tesla’s papers. Here’s what their own scientist actually found.

The FBI opened its file on Nikola Tesla in September 1940, more than two years before his death, after a private citizen mailed J. Edgar Hoover a New York Times interview in which Tesla described a weapon he called the teleforce, a device the press had already nicknamed the death ray. The letter-writer warned that if Tesla’s plans reached enemy hands, the consequences could be severe. Hoover’s office responded briefly and did not pursue it further at the time. The file, however, stayed open.

Tesla was eighty-four years old in 1940, largely destitute, and living alone in Room 3327 of the Hotel New Yorker. He would die there two years and four months later, on January 8, 1943.

Within hours of Tesla’s death, agents from the Office of Alien Property Custodian arrived at the Hotel New Yorker and removed his property: trunks of notebooks, technical drawings, correspondence, and experimental apparatus. A January 12, 1943 memo, four days later, records the government’s own internal awareness of a problem: Tesla had been a naturalized American citizen since 1891, and the Alien Property Custodian’s mandate covered the property of foreign nationals, not citizens. The memo notes the office believed it could hold the material for at least two days regardless, long enough for the War Department to review it.

The seized material went to a government warehouse. Separately, a hotel safe at the Governor Clinton Hotel, rumored to hold Tesla’s most sensitive weapon plans, was opened and found to contain a piece of electrical testing equipment, decades old, of no apparent significance.

Dr. John G. Trump, a high-voltage physicist affiliated with MIT and the National Defense Research Committee, was brought in to review the technical content of Tesla’s papers on behalf of the government. His review took three days. His conclusion, as it appears in FBI correspondence, was direct: the papers contained nothing of significant value to the country, and nothing that would constitute a hazard if it fell into unfriendly hands. On the specific question of the particle beam weapon Tesla had described publicly for years, Trump found the plans lacked sufficient technical detail to permit construction of a working device, and that anything buildable from the material would be of limited power and no military significance.

Trump’s formal written report itself has never been released as a standalone document in either the 2016 or 2018 FOIA publications. What the public record contains is FBI correspondence describing his findings, not the report in his own words. That distinction is one the file itself does not resolve.

This establishes that the U.S. government treated a private citizen’s deathbed papers as a potential weapons-proliferation risk serious enough to justify a same-day seizure of legally uncertain authority, that a qualified government-affiliated physicist reviewed the material and found no working weapon, and that this conclusion is now confirmed directly by the FBI’s own declassified file, not by later biography or speculation.

This does not establish what, if anything, in Tesla’s broader body of work held genuine unrealized value, nor does it explain why portions of the 2016 and 2018 releases remain redacted more than seventy years after the events they describe, nor does it produce Trump’s original report, which remains unreleased.

Forty years after Trump’s evaluation dismissed the feasibility of a directed-energy weapon, the U.S. government committed billions of dollars to exactly that concept. See the Strategic Defense Initiative, announced in 1983 →