The FBI Houston field office is investigating at a downtown Houston federal building as authorities investigate a series of suspicious mailings sent to addresses nationwide.
The investigation is happening now at the Mickey Leland building on Smith Street.
An envelope containing a suspicious substance was sent to Sen. Ted Cruz’s office, according to a law enforcement source.
“I am grateful to law enforcement for their professionalism and to my dedicated team members, who work tirelessly on behalf of Texans,” Cruz said on X.
This afternoon, my Houston office received a suspicious piece of mail containing a white powder substance. The FBI, Houston Police and Fire Department, and U.S. Capitol Police responded swiftly.
— Senator Ted Cruz (@SenTedCruz) October 16, 2026
I am grateful to law enforcement for their professionalism and to my dedicated team…
The FBI and the U.S. Postal Inspection Service are investigating the mailings, some of which contained an unknown substance, according to federal authorities.
The agencies are working with law enforcement partners to respond to each incident and identify the person or people responsible.

The suspicious letters were sent to various addresses across the country, including secretaries of state offices and their related election offices.
“The FBI and the U.S. Postal Inspection Service will continue to safeguard the public and secure elections for American citizens,” the FBI said in a statement.
A source familiar tells KPRC 2 News everyone in the senator’s office is safe.
FBI is on scene at Sen. Ted Cruz's downtown Houston office after a law enforcement source tells me his office received an envelope containing a white powder, similar to other suspicious mailings nationwide. A source familiar says everyone in the senator's office is safe. @KPRC2 pic.twitter.com/1Ro9QnDUka
— KPRC 2 Bryce Newberry (@KPRC2Bryce) October 16, 2026
Authorities have not released additional details, citing the ongoing investigation.
KPRC 2’s reporter Sandy Torres and photographer Mike Lemons are outside the federal building in downtown Houston.
We will continue to follow this developing story and provide updates as more information becomes available.