Suspicious Powder Mailed to Mike Thompson Napa Office

A letter containing unknown white powder was delivered to the congressman's office in Napa.

Updated on Oct. 20, 2026 in Terrorism

Bold flat-color editorial illustration showing a stark institutional archway, evoking the gravity of a federal investigation into threats against public officials. — Representative Mike Thompson's Napa office received a suspicious letter containing unknown white powder, prompting a federal investigation into the coordinated campaign. AI Illustration. Upload story photo >

Representative Mike Thompson's Napa office received an envelope containing an unknown white powder. No staff members were injured during the incident.

Why it matters

The mailing is part of a larger, coordinated campaign that has targeted more than three dozen members of Congress with similar items. Federal authorities are investigating the source of the letters to determine the nature of the substance and the motive behind the threats.

The incident has been referred to the FBI for a full investigation. Currently, no staff members have sustained injuries from the substance found in the envelope.

The players

Mike Thompson

Mike Thompson is a U.S. Representative serving the district that includes Napa and St. Helena.

Federal Bureau of Investigation

The Federal Bureau of Investigation is the primary federal agency responsible for investigating domestic threats and federal crimes.

The details

The suspicious envelope was mailed directly to Representative Thompson's congressional office in Napa. The representative confirmed the event in a public statement following the arrival of the letter.

The letter was received at the Napa office on October 19, 2026.

Legal Context

This incident follows a pattern established by the 2001 anthrax attacks, which set a high-stakes legal precedent for investigating mail-based threats against officials. Authorities now treat all such deliveries as federal crimes due to the significant disruption they cause to legislative operations.

The investigation by federal authorities may lead to increased security measures for local congressional offices in the area. Residents should remain aware that federal agencies are actively processing the site, though no public evacuation or hazardous zone has been declared.

The takeaway

Incidents involving suspicious mail are treated with high priority by law enforcement to ensure the safety of public staff. Recipients of unexpected or suspicious mail are encouraged to refrain from opening it and to contact local law enforcement immediately.