Federal prosecutors in Oklahoma have charged a 57-year-old Oklahoma City man with sending more than 700 threatening letters filled with white powder to members of Congress, state officials and other public figures in a sprawling election-eve hoax that, officials say, wasted emergency resources across the country and terrified recipients who feared they had been exposed to a biological weapon.
Robin Patrick Martin was arrested on November 2, 2026, and charged with conveying false information and hoaxes, the Justice Department said. The powder in the letters was not hazardous — it was yeast or flour — but investigators say the threats inside were explicit, warning recipients that they had been exposed to a deadly toxin and that they would die.
Martin made his first court appearance on Monday in the Western District of Oklahoma. A detention hearing is set for November 9, when a judge will decide whether he remains in custody while the case proceeds.
FBI white powder letters arrest: what happened on November 2
According to the criminal complaint, Martin mailed the letters over a period of weeks, targeting elected officials, government offices and private individuals. The letters were designed to look like a genuine biological threat: white powder spilled out when envelopes were opened, and the enclosed notes claimed the recipient had been poisoned.
The FBI said the investigation began after multiple recipients reported receiving suspicious envelopes. Local police, fire departments and hazardous materials teams responded to each incident, closing buildings, evacuating staff and testing the powder before the all-clear could be given.
Federal officials have not disclosed the full list of recipients, but the complaint describes a campaign aimed at officials in multiple states. The letters were sent to members of Congress, state lawmakers and other public officials, as well as people connected to election administration, according to prosecutors.
The 700 mailings: who received them and what they said
The sheer scale of the mailing campaign sets this case apart from typical hoax threats. More than 700 letters — a volume that required sustained effort to prepare, address and post — were mailed in a coordinated wave, prosecutors said.
Inside each envelope was a small amount of white powder and a note threatening the recipient with death from exposure. Some recipients were told they had already been exposed and should seek immediate medical attention, a claim designed to maximise panic even though the powder was harmless.
The letters arrived in the final days before the election, a timing prosecutors are likely to highlight as they argue the mailings were intended to intimidate officials and disrupt government work at a sensitive moment. The Justice Department has not said whether Martin acted alone or had any assistance in preparing the mailings.
How investigators traced the letters to Oklahoma City
Investigators traced the letters through postal records, surveillance footage and forensic evidence, according to the complaint. The FBI’s Joint Terrorism Task Force and the U.S. Postal Inspection Service worked together to identify the source of the mailings, narrowing the origin to the Oklahoma City area.
The complaint describes how agents linked the envelopes to Martin through a combination of postal markings, return-address information and other identifying details that pointed to a single sender. Agents then obtained a search warrant for his residence, where they found materials consistent with preparing the letters.
Those two kinds of evidence — movement through the postal system and physical materials found at a suspect’s home — are typical of how federal investigators build white-powder cases. In past hoax cases, prosecutors have relied on similar combinations of mail records and search evidence to prove a defendant prepared and sent the threatening letters.
Charges, court appearance and the November 9 detention hearing
Martin is charged with conveying false information and hoaxes, a federal offence that carries a maximum penalty of five years in prison. Prosecutors may add further charges as the investigation continues, including charges related to threatening federal officials.
At his initial appearance on Monday, Martin was advised of the charges and his rights. The court set a detention hearing for November 9, when prosecutors are expected to argue that he should remain in custody because of the scale of the alleged conduct and the risk that he could send further letters if released.
Defence counsel has not yet made a public statement about the case, and it is not clear whether Martin has entered a plea. The case is being prosecuted by the U.S. Attorney’s Office for the Western District of Oklahoma, with assistance from the FBI’s Oklahoma City field office.
Why the powder was not the real danger — but the threat was
White powder letters trigger a specific kind of emergency response, even when the powder turns out to be harmless. Because the substance could be anthrax, ricin or another biological agent, first responders must treat every incident as a potential bioterrorism event until laboratory testing proves otherwise.
That response is expensive and disruptive: buildings are evacuated, staff are decontaminated, and hazardous materials teams spend hours securing and testing the material. Multiplied across 700 incidents, the cost in emergency resources and lost working time is substantial, even though no one was physically harmed by the powder itself.
The psychological impact is also part of the harm prosecutors will emphasise. Recipients who opened envelopes and saw powder spill out believed, at least briefly, that they might die. For public officials already facing threats, that experience adds to a climate of intimidation that federal law is designed to punish.
What happens next in the federal case
The immediate next step is the November 9 detention hearing, followed by a preliminary hearing or grand jury presentation. Prosecutors will need to present evidence linking Martin to the mailings, including the postal and forensic evidence described in the complaint.
The case also sits within a broader pattern of threats against public officials that federal authorities have warned about in recent years. The white-powder hoax — sending harmless powder with a threatening note — is a tactic that has been used repeatedly because it creates maximum disruption with minimal cost to the sender.
For the recipients, the case may bring some reassurance that the sender has been identified, but the broader question of how to deter similar hoaxes remains. Federal officials say they will continue to investigate and prosecute white-powder threats aggressively, regardless of whether the substance turns out to be dangerous.
Sources
USN reviewed reporting from multiple outlets for this story. Read more from Al Jazeera, The Oklahoman and WCIA.